Locate apparatus for receiving environmental information regarding underground facility marking operations, and associated methods and systems

ABSTRACT

In a locate operation to detect a presence or absence of at least one underground facility using a locate device, an applied signal is transmitted to the at least one underground facility, and/or a magnetic field emitted from the at least one underground facility is detected. Environmental information is obtained regarding at least one environmental condition of an environment in which the locate device is used, and information relating to the signal transmission, field detection and/or environmental information is logged into local memory of the locate device.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit, under 35 U.S.C. §120, as acontinuation (CON) of U.S. Non-provisional application Ser. No.12/704,087, entitled “Locate Apparatus Having Enhanced Features forUnderground Facility Locate Operations, and Associated Methods andSystems,” filed on Feb. 11, 2010, under attorney docket no.D0687.70019US01.

Ser. No. 12/704,087 claims a priority benefit, under 35 U.S.C. §119(a),to Canadian application serial no. 2,692,115, entitled “Locate ApparatusHaving Enhanced Features for Underground Facility Locate Operations, andAssociated Methods and Systems,” filed on Feb. 10, 2010, under attorneydocket no. PAT 70830-1CA.

Ser. No. 12/704,087 claims a priority benefit, under 35 U.S.C. §119(e),to U.S. Provisional Application Ser. No. 61/151,578, entitled “Locatingequipment that has enhanced features for underground facility locateoperations,” filed on Feb. 11, 2009 under attorney docket numberD0687.70019US00.

Ser. No. 12/704,087 also claims a priority benefit, under 35 U.S.C.§119(e), to U.S. Provisional Application Ser. No. 61/232,112, entitled“Methods and apparatus for detecting and monitoring use of locatingequipment for out-of-tolerance conditions,” filed on Aug. 7, 2009 underattorney docket number D0687.70042US00.

Ser. No. 12/704,087 also claims a priority benefit, under 35 U.S.C.§120, as a continuation-in-part (CIP) of U.S. Non-provisionalapplication Ser. No. 12/571,329, entitled “Methods and Apparatus forGenerating Electronic Records of Locate Operations,” filed on Sep. 30,2009 under attorney docket number D0687.70054US00.

Ser. No. 12/571,329 in turn claims a priority benefit, under 35 U.S.C.§119(e), of U.S. Provisional Application Ser. No. 61/102,122, entitled“Combination Locate and Marking Device with a Data Acquisition SystemInstalled Therein, and Associated Methods,” filed on Oct. 2, 2008 underattorney docket number D0687.70010US00.

Each of the above-identified applications is incorporated by referenceherein in its entirety.

Ser. No. 12/704,087 also claims a priority benefit, under 35 U.S.C. §119(e), to U.S. Patent Application Ser. No. 61/235,519, entitled“Marking Device With Accelerometer and Local Data Storage,” filed Aug.20, 2009 under Attorney Docket Number D0687.70047US00.

BACKGROUND

Field service operations may be any operation in which companiesdispatch technicians and/or other staff to perform certain activities,for example, installations, services and/or repairs. Field serviceoperations may exist in various industries, examples of which include,but are not limited to, network installations, utility installations,security systems, construction, medical equipment, heating, ventilatingand air conditioning (HVAC) and the like.

An example of a field service operation in the construction industry isa so-called “locate and marking operation,” also commonly referred tomore simply as a “locate operation” (or sometimes merely as “a locate”).In a typical locate operation, a locate technician visits a work site inwhich there is a plan to disturb the ground (e.g., excavate, dig one ormore holes and/or trenches, bore, etc.) so as to determine a presence oran absence of one or more underground facilities (such as various typesof utility cables and pipes) in a dig area to be excavated or disturbedat the work site. In some instances, a locate operation may be requestedfor a “design” project, in which there may be no immediate plan toexcavate or otherwise disturb the ground, but nonetheless informationabout a presence or absence of one or more underground facilities at awork site may be valuable to inform a planning, permitting and/orengineering design phase of a future construction project.

In many states, an excavator who plans to disturb ground at a work siteis required by law to notify any potentially affected undergroundfacility owners prior to undertaking an excavation activity. Advancednotice of excavation activities may be provided by an excavator (oranother party) by contacting a “one-call center.” One-call centerstypically are operated by a consortium of underground facility ownersfor the purposes of receiving excavation notices and in turn notifyingfacility owners and/or their agents of a plan to excavate. As part of anadvanced notification, excavators typically provide to the one-callcenter various information relating to the planned activity, including alocation (e.g., address) of the work site and a description of the digarea to be excavated or otherwise disturbed at the work site.

FIG. 1 illustrates an example in which a locate operation is initiatedas a result of an excavator 1 providing an excavation notice to aone-call center 2. An excavation notice also is commonly referred to asa “locate request,” and may be provided by the excavator to the one-callcenter via an electronic mail message, information entry via a websitemaintained by the one-call center, or a telephone conversation betweenthe excavator and a technician at the one-call center. The locaterequest may include an address or some other location-relatedinformation describing the geographic location of a work site at whichthe excavation is to be performed, as well as a description of the digarea (e.g., a text description), such as its location relative tocertain landmarks and/or its approximate dimensions, within which thereis a plan to disturb the ground at the work site. One-call centerssimilarly may receive locate requests for design projects (for which, asdiscussed above, there may be no immediate plan to excavate or otherwisedisturb the ground).

Using the information provided in a locate request for plannedexcavation or design projects, the one-call center identifies certainunderground facilities that may be present at the indicated work site.For this purpose, many one-call centers typically maintain a collectionof “polygon maps” which indicate, within a given geographic area overwhich the one-call center has jurisdiction, generally where undergroundfacilities may be found relative to some geographic reference frame orcoordinate system.

Polygon maps typically are provided to the one-call centers byunderground facilities owners within the jurisdiction of the one callcenter (“members” of the one-call center). A one-call center firstprovides the facility owner/member with one or more maps (e.g., streetor property maps) within the jurisdiction, on which are superimposedsome type of grid or coordinate system employed by the one-call centeras a geographic frame of reference. Using the maps provided by theone-call center, the respective facilities owners/members draw one ormore polygons on each map to indicate an area within which theirfacilities generally are disposed underground (without indicating thefacilities themselves). These polygons themselves do not preciselyindicate geographic locations of respective underground facilities;rather, the area enclosed by a given polygon generally provides anover-inclusive indication of where a given facilities owner'sunderground facilities are disposed. Different facilities owners/membersmay draw polygons of different sizes around areas including theirunderground facilities, and in some instances such polygons can coverappreciably large geographic regions (e.g., an entire subdivision of aresidential area), which may further obfuscate the actual/preciselocation of respective underground facilities.

Based on the polygon maps collected from the facilities owners/members,the one-call center may in some instances create composite polygon mapsto show polygons of multiple different members on a single map. Whetherusing single member or composite polygon maps, the one-call centerexamines the address or location information provided in the locaterequest and identifies a significant buffer zone around an identifiedwork site so as to make an over-inclusive identification of facilitiesowners/members that may have underground facilities present (e.g., toerr on the side of caution). In particular, based on this generallyover-inclusive buffer zone around the identified work site (and in someinstances significantly over-inclusive buffer zone), the one-call centerconsults the polygon maps to identify which member polygons intersectwith all or a portion of the buffer zone so as to notify theseunderground facility owners/members and/or their agents of the proposedexcavation or design project. Again, it should be appreciated that thebuffer zones around an indicated work site utilized by one-call centersfor this purpose typically embrace a geographic area that includes butgoes well beyond the actual work site, and in many cases the geographicarea enclosed by a buffer zone is significantly larger than the actualdig area in which excavation or other similar activities are planned.Similarly, as noted above, the area enclosed by a given member polygongenerally does not provide a precise indication of where one or moreunderground facilities may in fact be found.

In some instances, one-call centers may also or alternatively haveaccess to various existing maps of underground facilities in theirjurisdiction, referred to as “facilities maps.” Facilities mapstypically are maintained by facilities owners/members within thejurisdiction and show, for respective different utility types, whereunderground facilities purportedly may be found relative to somegeographic reference frame or coordinate system (e.g., a grid, a streetor property map, GPS latitude and longitude coordinates, etc.).Facilities maps generally provide somewhat more detail than polygon mapsprovided by facilities owners/members; however, in some instances theinformation contained in facilities maps may not be accurate and/orcomplete. For at least this reason, whether using polygon maps orfacilities maps, as noted above the one-call center utilizes asignificant buffer zone around an identified work site so as to make anover-inclusive identification of facilities owners/members that may haveunderground facilities present.

Once facilities implicated by the locate request are identified by aone-call center (e.g., via the polygon map/buffer zone process), theone-call center generates a “locate request ticket” (also known as a“locate ticket,” or simply a “ticket”). The locate request ticketessentially constitutes an instruction to inspect a work site andtypically identifies the work site of the proposed excavation or designand a description of the dig area, typically lists on the ticket all ofthe underground facilities that may be present at the work site (e.g.,by providing a member code for the facility owner whose polygon fallswithin a given buffer zone), and may also include various otherinformation relevant to the proposed excavation or design (e.g., thename of the excavation company, a name of a property owner or partycontracting the excavation company to perform the excavation, etc.). Theone-call center sends the ticket to one or more underground facilityowners 4 and/or one or more locate service providers 3 (who may beacting as contracted agents of the facility owners) so that they canconduct a locate and marking operation to verify a presence or absenceof the underground facilities in the dig area. For example, in someinstances, a given underground facility owner 4 may operate its ownfleet of locate technicians (e.g., locate technician 6), in which casethe one-call center 2 may send the ticket to the underground facilityowner 4. In other instances, a given facility owner may contract with alocate service provider to receive locate request tickets and perform alocate and marking operation in response to received tickets on theirbehalf.

Upon receiving the locate request, a locate service provider or afacility owner (hereafter referred to as a “ticket recipient”) maydispatch a locate technician 5 to the work site of planned excavation todetermine a presence or absence of one or more underground facilities inthe dig area to be excavated or otherwise disturbed. A typical firststep for the locate technician 5 includes utilizing an undergroundfacility “locate device,” which is an instrument or set of instruments(also referred to commonly as a “locate set”) for detecting facilitiesthat are concealed in some manner, such as cables and pipes that arelocated underground. The locate device is employed by the technician toverify the presence or absence of underground facilities indicated inthe locate request ticket as potentially present in the dig area (e.g.,via the facility owner member codes listed in the ticket). This processis often referred to as a “locate operation.”

In one example of a locate operation, an underground facility locatedevice is used to detect electromagnetic fields that are generated by anapplied signal provided along a length of a target facility to beidentified. In this example, a locate device may include both a signaltransmitter to provide the applied signal (e.g., which is coupled by thelocate technician to a tracer wire disposed along a length of afacility), and a signal receiver which is generally a hand-heldapparatus carried by the locate technician as the technician walksaround the dig area to search for underground facilities. FIG. 2illustrates a conventional locate device 20 (indicated by the dashedbox) that includes a transmitter 22 and a locate receiver 24. Thetransmitter 22 is connected, via a connection point 26, to a targetobject (in this example, underground facility 28) located in the ground21. The transmitter generates the applied signal 23, which is coupled tothe underground facility via the connection point (e.g., to a tracerwire along the facility), resulting in the generation of a magneticfield 25. The magnetic field in turn is detected by the locate receiver24, which itself may include one or more detection antenna (not shown).The locate receiver 24 indicates a presence of a facility when itdetects electromagnetic fields arising from the applied signal 23.Conversely, the absence of a signal detected by the locate receivergenerally indicates the absence of the target facility.

In yet another example, a locate device employed for a locate operationmay include a single instrument, similar in some respects to aconventional metal detector. In particular, such an instrument mayinclude an oscillator to generate an alternating current that passesthrough a coil, which in turn produces a first magnetic field. If apiece of electrically conductive metal is in close proximity to the coil(e.g., if an underground facility having a metal component is below/nearthe coil of the instrument), eddy currents are induced in the metal andthe metal produces its own magnetic field, which in turn affects thefirst magnetic field. The instrument may include a second coil tomeasure changes to the first magnetic field, thereby facilitatingdetection of metallic objects.

In addition to the locate operation, the locate technician alsogenerally performs a “marking operation,” in which the technician marksthe presence (and in some cases the absence) of a given undergroundfacility in the dig area based on the various signals detected (or notdetected) during the locate operation. For this purpose, the locatetechnician conventionally utilizes a “marking device” to dispense amarking material on, for example, the ground, pavement, or other surfacealong a detected underground facility. Marking material may be anymaterial, substance, compound, and/or element, used or which may be usedseparately or in combination to mark, signify, and/or indicate. Examplesof marking materials may include, but are not limited to, paint, chalk,dye, and/or iron. Marking devices, such as paint marking wands and/orpaint marking wheels, provide a convenient method of dispensing markingmaterials onto surfaces, such as onto the surface of the ground orpavement.

FIGS. 3A and 3B illustrate a conventional marking device 50 with amechanical actuation system to dispense paint as a marker. Generallyspeaking, the marking device 50 includes a handle 38 at a proximal endof an elongated shaft 36 and resembles a sort of “walking stick,” suchthat a technician may operate the marking device while standing/walkingin an upright or substantially upright position. A marking dispenserholder 40 is coupled to a distal end of the shaft 36 so as to containand support a marking dispenser 56, e.g., an aerosol paint can having aspray nozzle 54. Typically, a marking dispenser in the form of anaerosol paint can is placed into the holder 40 upside down, such thatthe spray nozzle 54 is proximate to the distal end of the shaft (closeto the ground, pavement or other surface on which markers are to bedispensed).

In FIGS. 3A and 3B, the mechanical actuation system of the markingdevice 50 includes an actuator or mechanical trigger 42 proximate to thehandle 38 that is actuated/triggered by the technician (e.g., viapulling, depressing or squeezing with fingers/hand). The actuator 42 isconnected to a mechanical coupler 52 (e.g., a rod) disposed inside andalong a length of the elongated shaft 36. The coupler 52 is in turnconnected to an actuation mechanism 58, at the distal end of the shaft36, which mechanism extends outward from the shaft in the direction ofthe spray nozzle 54. Thus, the actuator 42, the mechanical coupler 52,and the actuation mechanism 58 constitute the mechanical actuationsystem of the marking device 50.

FIG. 3A shows the mechanical actuation system of the conventionalmarking device 50 in the non-actuated state, wherein the actuator 42 is“at rest” (not being pulled) and, as a result, the actuation mechanism58 is not in contact with the spray nozzle 54. FIG. 3B shows the markingdevice 50 in the actuated state, wherein the actuator 42 is beingactuated (pulled, depressed, squeezed) by the technician. When actuated,the actuator 42 displaces the mechanical coupler 52 and the actuationmechanism 58 such that the actuation mechanism contacts and appliespressure to the spray nozzle 54, thus causing the spray nozzle todeflect slightly and dispense paint. The mechanical actuation system isspring-loaded so that it automatically returns to the non-actuated state(FIG. 3A) when the actuator 42 is released.

In some environments, arrows, flags, darts, or other types of physicalmarks may be used to mark the presence or absence of an undergroundfacility in a dig area, in addition to or as an alternative to amaterial applied to the ground (such as paint, chalk, dye, tape) alongthe path of a detected utility. The marks resulting from any of a widevariety of materials and/or objects used to indicate a presence orabsence of underground facilities generally are referred to as “locatemarks.” Often, different color materials and/or physical objects may beused for locate marks, wherein different colors correspond to differentutility types. For example, the American Public Works Association (APWA)has established a standardized color-coding system for utilityidentification for use by public agencies, utilities, contractors andvarious groups involved in ground excavation (e.g., red=electric powerlines and cables; blue=potable water; orange=telecommunication lines;yellow=gas, oil, steam). In some cases, the technician also may provideone or more marks to indicate that no facility was found in the dig area(sometimes referred to as a “clear”).

As mentioned above, the foregoing activity of identifying and marking apresence or absence of one or more underground facilities generally isreferred to for completeness as a “locate and marking operation.”However, in light of common parlance adopted in the constructionindustry, and/or for the sake of brevity, one or both of the respectivelocate and marking functions may be referred to in some instances simplyas a “locate operation” or a “locate” (i.e., without making any specificreference to the marking function). Accordingly, it should beappreciated that any reference in the relevant arts to the task of alocate technician simply as a “locate operation” or a “locate” does notnecessarily exclude the marking portion of the overall process. At thesame time, in some contexts a locate operation is identified separatelyfrom a marking operation, wherein the former relates more specificallyto detection-related activities and the latter relates more specificallyto marking-related activities.

Inaccurate locating and/or marking of underground facilities can resultin physical damage to the facilities, property damage, and/or personalinjury during the excavation process that, in turn, can expose afacility owner or contractor to significant legal liability. Whenunderground facilities are damaged and/or when property damage orpersonal injury results from damaging an underground facility during anexcavation, the excavator may assert that the facility was notaccurately located and/or marked by a locate technician, while thelocate contractor who dispatched the technician may in turn assert thatthe facility was indeed properly located and marked. Proving whether theunderground facility was properly located and marked can be difficultafter the excavation (or after some damage, e.g., a gas explosion),because in many cases the physical locate marks (e.g., the markingmaterial or other physical marks used to mark the facility on thesurface of the dig area) will have been disturbed or destroyed duringthe excavation process (and/or damage resulting from excavation).

Previous efforts at documenting locate operations have focused primarilyon locate devices that employ electromagnetic fields to determine thepresence of an underground facility. For example, U.S. Pat. No.5,576,973, naming inventor Alan Haddy and entitled “Apparatus and Methodfor Obtaining Geographical Positional Data for an Object LocatedUnderground” (hereafter “Haddy”), is directed to a locate device (i.e.,a “locator”) that receives and stores data from a global positioningsystem (“GPS”) to identify the position of the locate device as anunderground object (e.g., a cable) is detected by the locate device.Haddy notes that by recording geographical position data relating to thedetected underground object, there is no need to physically mark thelocation of the underground object on the ground surface, and therecorded position data may be used in the future to re-locate theunderground object.

Similarly, U.S. Pat. No. 7,319,387, naming inventors Willson et al. andentitled “GPS Interface for Locating Device” (hereafter “Willson”), isdirected to a locate device for locating “position markers,” i.e.,passive antennas that reflect back RF signals and which are installedalong buried utilities. In Willson, a GPS device may be communicativelycoupled to the locate device, or alternatively provided as an integralpart of the locate device, to store GPS coordinate data associated withposition markers detected by the locate device. Electronic memory isprovided in the locate device for storing a data record of the GPScoordinate data, and the data record may be uploaded to a remotecomputer and used to update a mapping database for utilities.

U.S. Publication No. 2006/0282280, naming inventors Stotz et al. andentitled “Ticket and Data Management” (hereafter “Stotz”), also isdirected to a locate device (i.e., a “locator”) including a GPSreceiver. Upon detection of the presence of a utility line, Stotz'locate device can update ticket data with GPS coordinates for thedetected utility line. Once the locate device has updated the ticketdata, the reconfigured ticket data may be transmitted to a network.

U.S. Publication No. 2007/0219722, naming inventors Sawyer, Jr. et al.and entitled “System and Method for Collecting and Updating GeographicalData” (hereafter “Sawyer”), is directed to collecting and recording datarepresentative of the location and characteristics of utilities andinfrastructure in the field for creating a grid or map. Sawyer employs afield data collection unit including a “locating pole” that is placed ontop of or next to a utility to be identified and added to the grid ormap. The locating pole includes an antenna coupled to a locationdetermination system, such as a GPS unit, to provide longitudinal andlatitudinal coordinates of the utility under or next to the end of thelocating pole. The data gathered by the field data collection unit issent to a server to provide a permanent record that may be used fordamage prevention and asset management operations.

SUMMARY

Applicants have recognized and appreciated that uncertainties which maybe attendant to locate and marking operations may be significantlyreduced by collecting comprehensive information relating to one or bothof the operating conditions of equipment used to perform the locateand/or marking operations, as well as various environmental conditionspresent at or near the work site and/or in close proximity to theequipment being used.

More specifically, Applicants have recognized and appreciated thatconventional techniques for using a locate device to detect undergroundfacilities are sometimes tentative and typically iterative in nature,and use of locate devices with only rudimentary GPS capabilities in someinstances may result in redundant, spurious and/or incomplete geographiclocation data collected by such devices. For example, during a typicallocate operation, a technician attempting to locate an undergroundfacility with a locate device often needs to sweep an appreciable areaaround a suspected underground facility, and make multiple passes withthe locate device over the underground facility to obtain meaningfuldetection signals. Furthermore, the technician often needs to relysignificantly on visual observations of the area, including relevantlandmarks such as facility connections to buildings, transformer boxes,maintenance/public access points, curbs, sidewalks, roadways, etc., toeffectively deduce a sensible path of an underground facility to belocated. The foregoing is particularly true if at some point during thelocate operation the technician loses a signal from an undergroundfacility in the process of being detected (e.g., due to a brokentransmitter circuit path from a damaged tracer wire, and loss of thetransmitter test signal). Thus, collecting and logging geographiclocation information throughout this process may result in excessiveand/or imprecise data, or in some instances incomplete relevant data(e.g., in the case of signal loss/broken tracer wire), from which it maybe difficult to cull the data that is truly complete and representativeof where the underground facility ultimately was detected. Accordingly,additional information about other operating conditions of the locatedevice, and/or information on existing environmental conditions, may insome instances supplement, or facilitate identification of, informationthat is perhaps the most relevant to the operation at hand.

In view of the foregoing, various embodiments of the present inventionare directed to locate devices (e.g., locate transmitters and/or locatereceivers) with enhanced features, and associated methods and systems,to facilitate collection of a wide variety of information relating to alocate operation, and provide for creation of a comprehensive and robustelectronic record of a locate operation. Locate information relating touse of a locate device to perform a locate operation may be acquiredfrom one or more of a variety of input devices in any of a variety ofmanners, logged/stored in local memory of a locate device, formatted invarious manners, processed and/or analyzed at the locate device itself,and/or transmitted to another device (e.g., a remote computer/server)for storage, processing and/or analysis.

In some exemplary embodiments described in detail herein, a locatedevice may include one or more environmental sensors and/or operationalsensors, and the locate information may include environmentalinformation and operational information derived from such sensors.Environmental and/or operational information may be used to controloperation of the locate device, assess out-of-tolerance conditions inconnection with use of the locate device, and/or provide alerts or otherfeedback. In yet other embodiments, additional enhancements aredisclosed relating to improving the determination of a location (e.g.,GPS coordinates) of a detecting tip of the locate device (e.g., aportion of the locate device close to the ground, pavement or othersurface below which one or more underground facilities may be disposed)during use.

In other embodiments, a locate device may be operated in a “solo” modeor a “group” mode. In particular, in a “solo” mode, the locate devicemay be operated as an individual, independent device to collect, storeand/or transmit data, whereas in “group” mode, a locate device may actas a “worker” device or a “leader” device to facilitate consolidation ofdata collected by multiple devices (e.g., and relating to a same ticket)at a single one of the devices, at a host server, or at any othersuitable location.

In yet other embodiments, a locate device may be equipped with anenhanced user interface having tactile functionality; in particular, thelocate device may include one or more tactile indicators (e.g.,vibrating devices) disposed, for example, in a handle, joy stick,actuator or elsewhere on the device, to provide a tactile indication toa technician using the locate device (e.g., as feedback in connectionwith an operating mode, operating condition, environmental condition,etc.).

During and/or following collection and/or storage of informationregarding the locate operation, data compiled in one or more electronicrecords associated with the locate operation may be accessed, processedand/or analyzed to provide further information relating to theperformance of the locate operation. For example, in other embodimentsdisclosed herein, data from one or more electronic records of the locateoperation is processed so as to electronically render (visuallyrecreate) the locate operation (e.g., on a display device associatedwith the locate device or other display device). Electronic renderingsmay be generated statically (e.g., in which all available data in anelectronic record is rendered essentially simultaneously on an availabledisplay field) or in an “animated” time-sequenced recreation of thelocate operation (e.g., based on at least timing and geographic locationinformation in the electronic record) once an electronic record isgenerated. In yet another exemplary implementation, various informationto be logged in an electronic record may be passed/transmitted inessentially real-time to one or more display devices to facilitate anessentially real-time electronic rendering on an available display fieldof a locate operation in process.

One embodiment of the present invention is directed to an apparatus fordetecting a presence or absence of an underground facility. Theapparatus comprises at least one receiver antenna configured to detect amagnetic field from the underground facility, at least one processorcommunicatively coupled to the at least one receiver antenna to receiveinformation about the magnetic field from the at least one receiverantenna, and at least one input device communicatively coupled to the atleast one processor and configured to sense at least one environmentalcondition of an environment in which the apparatus is located. The atleast one input device is configured to provide an output signal to theat least one processor indicative of the sensed at least oneenvironmental condition.

Another embodiment of the present invention is directed to an apparatusfor detecting a presence or absence of an underground facility. Theapparatus comprises at least one receiver antenna configured to detect amagnetic field from the underground facility, an actuator, and at leastone processor communicatively coupled to the at least one receiverantenna to receive information about the magnetic field from the atleast one receiver antenna in response to actuation of the actuator. Theapparatus further comprises a location tracking system communicativelycoupled to the at least one processor and configured to determine alocation of the apparatus, and at least one input device communicativelycoupled to the at least one processor and configured to sense at leastone environmental condition of an environment in which the apparatus islocated. The at least one input device is configured to provide anoutput signal to the at least one processor indicative of the sensed atleast one environmental condition. The at least one processor isprogrammed with processor-executable instructions which, when executed,cause the at least one processor to compare the output signal of the atleast one input device to at least one target range. In response todetermining that the output signal is outside the at least one targetrange, the at least one processor does at least one of (i) generate analert to a technician using the apparatus and (ii) disable the actuator.

Another embodiment of the present invention is directed to a method forperforming a locate operation for at least one underground facilityusing a locate apparatus. The method comprises A) detecting, via atleast one receiver antenna of the apparatus, a magnetic field from theat least one underground facility. The method further comprises B)detecting, via at least one input device of the apparatus, at least oneenvironmental condition of an environment in which the apparatus islocated. The method further comprises C) logging into local memory ofthe apparatus locate information relating at least in part to A) and B).

Another embodiment of the present invention is directed to an apparatusfor detecting a presence or absence of an underground facility, theapparatus comprising at least one receiver antenna configured to detecta magnetic field from the underground facility, and at least oneprocessor communicatively coupled to the at least one receiver antennato receive information about the magnetic field from the at least onereceiver antenna. The apparatus further comprises at least one actuatorcommunicatively coupled to the at least one processor and the at leastone receiver antenna and configured to cause the at least one processorto log the information about the magnetic field into local memory uponactuation of the at least one actuator. The apparatus further comprisesan input device communicatively coupled to the at least one processor toprovide an input signal to the at least one processor. The at least oneprocessor is programmed with processor-executable instructions which,when executed, cause the at least one processor to compare the inputsignal to a target value or range of values to assess whether anout-of-tolerance condition is indicated by the input signal. If anout-of-tolerance condition is indicated by the input signal, the atleast one processor does at least one of: (a) log an out-of-toleranceindication into an electronic record; (b) generate an alert to a user ofthe apparatus that an out-of-tolerance condition has been detected; and(c) disable the at least one actuator.

Another embodiment of the present invention is directed to a method ofusing a locate receiver for performing a locate operation for detectinga presence or absence of at least one underground facility. The methodcomprises A) acquiring, using an environmental sensor or operationalsensor of the locate receiver, information comprising: (i) environmentalinformation representative of at least one environmental condition of anenvironment in which the locate receiver is located; and/or (ii)operational information representative of at least one operatingcondition of the locate receiver. The method further comprises B)detecting a magnetic field from the at least one underground facilityusing at least one receiver antenna of the locate receiver. The methodfurther comprises C) controlling B) based at least in part on theenvironmental information and/or operational information acquired in A).

Another embodiment of the present invention is directed to a method forusing operational data collected as part of a locate operation to detectthe presence or absence of an underground facility. The method comprisesreceiving the operational data representative of an operating conditionof a locate receiver used to perform the locate operation, and analyzingthe operational data for an operating pattern of a technician using thelocate receiver.

Another embodiment of the present invention is directed to at least onecomputer-readable storage medium storing an electronic record associatedwith a locate operation. The electronic record comprises at least onedata set representing a technician signature with respect to atechnician's operation of a locate receiver for performing the locateoperation.

Another embodiment of the present invention is directed to a locatetransmitter for use in a locate operation to detect the presence orabsence of an underground facility. The locate transmitter comprisestransmitter circuitry configured to generate an applied signal to beapplied along the underground facility, at least one processorcommunicatively coupled to the transmitter circuitry, and at least oneinput device communicatively coupled to the at least one processor andconfigured to sense at least one environmental condition of anenvironment in which the locate transmitter is located. The at least oneinput device is configured to provide an output signal to the at leastone processor indicative of the sensed at least one environmentalcondition.

Another embodiment of the present invention is directed to a method ofusing a locate transmitter in a locate operation to detect a presence orabsence of an underground facility. The method comprises A) generatingan applied signal to be applied along the underground facility. Themethod further comprises B) detecting, via at least one input device ofthe locate transmitter, at least one environmental condition of anenvironment in which the locate transmitter is located. The methodfurther comprises C) logging into local memory of the locate transmitterlocate information relating at least in part to A) and B).

Another embodiment of the present invention is directed to a locatetransmitter for use in a locate operation to detect a presence orabsence of an underground facility, comprising transmitter circuitryconfigured to generate an applied signal to be applied along theunderground facility, and at least one processor communicatively coupledto the transmitter circuitry. The locate transmitter further comprisesat least one input device communicatively coupled to the at least oneprocessor and configured to sense at least one operating condition ofthe locate transmitter. The at least one input device is configured toprovide an output signal to the at least one processor indicative of thesensed at least one operating condition.

Another embodiment of the present invention is directed to a method ofusing a locate transmitter in a locate operation to detect a presence orabsence of an underground facility, the method comprising A) generatingan applied signal to be applied along the underground facility. Themethod further comprises B) detecting, via at least one input device ofthe locate transmitter, at least one operating condition of the locatetransmitter. The method further comprises C) logging into local memoryof the locate transmitter locate information relating at least in partto A) and B).

Another embodiment of the present invention is directed to a locatetransmitter for generating an applied signal for use in a locateoperation for detecting a presence or absence of an undergroundfacility. The locate transmitter comprises transmitter circuitryconfigured to generate an applied signal to be applied along theunderground facility, at least one processor communicatively coupled tothe transmitter circuitry, and an input device communicatively coupledto the at least one processor to provide an input signal to the at leastone processor. The at least one processor is programmed withprocessor-executable instructions which, when executed, cause the atleast one processor to compare the input signal to a target value orrange of values to assess whether an out-of-tolerance condition isindicated by the input signal. If an out-of-tolerance condition isindicated by the input signal, the at least one processor does at leastone of: (a) log an out-of-tolerance indication into an electronicrecord; (b) generate an alert to a user of the locate transmitter thatan out-of-tolerance condition has been detected; and (c) disable thetransmitter circuitry.

Another embodiment of the present invention is directed to a method ofusing a locate transmitter for performing a locate operation fordetecting a presence or absence of at least one underground facility.The method comprises A) generating an applied signal, and B) providingthe applied signal to the at least one underground facility. The methodfurther comprises C) acquiring, using an environmental sensor oroperational sensor of the locate transmitter, information comprising:(i) environmental information representative of at least oneenvironmental condition of an environment in which the locatetransmitter is located; and/or (ii) operational informationrepresentative of at least one operating condition of the locatetransmitter. The method further comprises D) controlling A) based atleast in part on the environmental information and/or operationalinformation acquired in C).

Another embodiment of the present invention is directed to an apparatusfor detecting a presence or absence of an underground facility. Theapparatus comprises at least one receiver antenna configured to detect amagnetic field from the underground facility, a memory to storeprocessor-executable instructions, at least one communication interface,and at least one processor communicatively coupled to the at least onereceiver antenna, the memory, and the at least one communicationinterface. Upon execution of the processor-executable instructions, theat least one processor controls the at least one communication interfaceto receive environmental information regarding at least oneenvironmental condition of an environment in which the apparatus islocated, and stores at least some of the received environmentalinformation in the memory.

Another embodiment of the present invention is directed to a locateapparatus for performing a locate operation to detect a presence or anabsence of at least one underground facility. The apparatus comprises atleast one receiver antenna to detect a magnetic field from at least oneunderground facility when present. The apparatus further comprises atleast one input device to provide environmental information regardingthe locate operation. The at least one input device is configured tosense at least one environmental condition of an environment in whichthe apparatus is located and provide an output signal indicative of thesensed at least one environmental condition. The apparatus furthercomprises at least one processor communicatively coupled to the at leastone receiver antenna and the at least one input device so as to receivethe output signal. In one implementation, the apparatus furthercomprises a memory to store processor-executable instructions. In oneaspect of this implementation, upon execution of theprocessor-executable instructions, the processor logs into the memory atleast some of the environmental information. In another aspect, theapparatus includes an actuator, and the processor logs into the memorythe at least some of the environmental information based at least inpart on at least one actuation of the actuator.

For purposes of the present disclosure, the term “dig area” refers to aspecified area of a work site within which there is a plan to disturbthe ground (e.g., excavate, dig holes and/or trenches, bore, etc.), andbeyond which there is no plan to excavate in the immediate surroundings.Thus, the metes and bounds of a dig area are intended to providespecificity as to where some disturbance to the ground is planned at agiven work site. It should be appreciated that a given work site mayinclude multiple dig areas.

The term “facility” refers to one or more lines, cables, fibers,conduits, transmitters, receivers, or other physical objects orstructures capable of or used for carrying, transmitting, receiving,storing, and providing utilities, energy, data, substances, and/orservices, and/or any combination thereof. The term “undergroundfacility” means any facility beneath the surface of the ground. Examplesof facilities include, but are not limited to, oil, gas, water, sewer,power, telephone, data transmission, cable television (TV), and/orinternet services.

The term “locate device” includes one or both of a locate transmitterand a locate receiver (which in some instances may also be referred tocollectively as a “locate instrument set,” or simply “locate set”).

The term “marking device” refers to any apparatus, mechanism, or otherdevice that employs a marking dispenser for causing a marking materialand/or marking object to be dispensed, or any apparatus, mechanism, orother device for electronically indicating (e.g., logging in memory) alocation, such as a location of an underground facility. Additionally,the term “marking dispenser” refers to any apparatus, mechanism, orother device for dispensing and/or otherwise using, separately or incombination, a marking material and/or a marking object. An example of amarking dispenser may include, but is not limited to, a pressurized canof marking paint. The term “marking material” means any material,substance, compound, and/or element, used or which may be usedseparately or in combination to mark, signify, and/or indicate. Examplesof marking materials may include, but are not limited to, paint, chalk,dye, and/or iron. The term “marking object” means any object and/orobjects used or which may be used separately or in combination to mark,signify, and/or indicate. Examples of marking objects may include, butare not limited to, a flag, a dart, and arrow, and/or an RFID markingball. It is contemplated that marking material may include markingobjects. It is further contemplated that the terms “marking materials”or “marking objects” may be used interchangeably in accordance with thepresent disclosure.

The term “locate mark” means any mark, sign, and/or object employed toindicate the presence or absence of any underground facility. Examplesof locate marks may include, but are not limited to, marks made withmarking materials, marking objects, global positioning or otherinformation, and/or any other means. Locate marks may be represented inany form including, without limitation, physical, visible, electronic,and/or any combination thereof.

The terms “actuate” or “trigger” (verb form) are used interchangeably torefer to starting or causing any device, program, system, and/or anycombination thereof to work, operate, and/or function in response tosome type of signal or stimulus. Examples of actuation signals orstimuli may include, but are not limited to, any local or remote,physical, audible, inaudible, visual, non-visual, electronic,mechanical, electromechanical, biomechanical, biosensing or othersignal, instruction, or event. The terms “actuator” or “trigger” (nounform) are used interchangeably to refer to any method or device used togenerate one or more signals or stimuli to cause or causing actuation.Examples of an actuator/trigger may include, but are not limited to, anyform or combination of a lever, switch, program, processor, screen,microphone for capturing audible commands, and/or other device ormethod. An actuator/trigger may also include, but is not limited to, adevice, software, or program that responds to any movement and/orcondition of a user, such as, but not limited to, eye movement, brainactivity, heart rate, other data, and/or the like, and generates one ormore signals or stimuli in response thereto. In the case of a markingdevice or other marking mechanism (e.g., to physically or electronicallymark a facility or other feature), actuation may cause marking materialto be dispensed, as well as various data relating to the markingoperation (e.g., geographic location, time stamps, characteristics ofmaterial dispensed, etc.) to be logged in an electronic file stored inmemory. In the case of a locate device or other locate mechanism (e.g.,to physically locate a facility or other feature), actuation may cause adetected signal strength, signal frequency, depth, or other informationrelating to the locate operation to be logged in an electronic filestored in memory.

The terms “locate and marking operation,” “locate operation,” and“locate” generally are used interchangeably and refer to any activity todetect, infer, and/or mark the presence or absence of an undergroundfacility. In some contexts, the term “locate operation” is used to morespecifically refer to detection of one or more underground facilities,and the term “marking operation” is used to more specifically refer tousing a marking material and/or one or more marking objects to mark apresence or an absence of one or more underground facilities. The term“locate technician” refers to an individual performing a locateoperation. A locate and marking operation often is specified inconnection with a dig area, at least a portion of which may be excavatedor otherwise disturbed during excavation activities.

The term “user” refers to an individual utilizing a locate device and/ora marking device and may include, but is not limited to, land surveyors,locate technicians, and support personnel.

The terms “locate request” and “excavation notice” are usedinterchangeably to refer to any communication to request a locate andmarking operation. The term “locate request ticket” (or simply “ticket”)refers to any communication or instruction to perform a locateoperation. A ticket might specify, for example, the address ordescription of a dig area to be marked, the day and/or time that the digarea is to be marked, and/or whether the user is to mark the excavationarea for certain gas, water, sewer, power, telephone, cable television,and/or some other underground facility. The term “historical ticket”refers to past tickets that have been completed.

The following U.S. published applications and patents are herebyincorporated herein by reference:

U.S. Pat. No. 7,640,105, issued Dec. 29, 2009, filed Mar. 13, 2007, andentitled “Marking System and Method With Location and/or Time Tracking;”

U.S. publication no. 2008-0245299-A1, published Oct. 9, 2008, filed Apr.4, 2007, and entitled “Marking System and Method;”

U.S. publication no. 2009-0013928-A1, published January 15, 2009, filedSep. 24, 2008, and entitled “Marking System and Method;”

U.S. publication no. 2009-0238414-A1, published September 24, 2009,filed Mar. 18, 2008, and entitled “Virtual White Lines for DelimitingPlanned Excavation Sites;”

U.S. publication no. 2009-0241045-A1, published Sep. 24, 2009, filedSep. 26, 2008, and entitled “Virtual White Lines for Delimiting PlannedExcavation Sites;”

U.S. publication no. 2009-0238415-A1, published Sep. 24, 2009, filedSep. 26, 2008, and entitled “Virtual White Lines for Delimiting PlannedExcavation Sites;”

U.S. publication no. 2009-0241046-A1, published Sep. 24, 2009, filedJan. 16, 2009, and entitled “Virtual White Lines for Delimiting PlannedExcavation Sites;”

U.S. publication no. 2009-0238416-A1, published Sep. 24, 2009, filedJan. 16, 2009, and entitled “Virtual White Lines for Delimiting PlannedExcavation Sites;”

U.S. publication no. 2009-0237408-A1, published Sep. 24, 2009, filedJan. 16, 2009, and entitled “Virtual White Lines for Delimiting PlannedExcavation Sites;”

U.S. publication no. 2009-0202101-A1, published Aug. 13, 2009, filedFeb. 12, 2008, and entitled “Electronic Manifest of Underground FacilityLocate Marks;”

U.S. publication no. 2009-0202110-A1, published Aug. 13, 2009, filedSep. 11, 2008, and entitled “Electronic Manifest of Underground FacilityLocate Marks;”

U.S. publication no. 2009-0201311-A1, published Aug. 13, 2009, filedJan. 30, 2009, and entitled “Electronic Manifest of Underground FacilityLocate Marks;”

U.S. publication no. 2009-0202111-A1, published Aug. 13, 2009, filedJan. 30, 2009, and entitled “Electronic Manifest of Underground FacilityLocate Marks;”

U.S. publication no. 2009-0204625-A1, published Aug. 13, 2009, filedFeb. 5, 2009, and entitled “Electronic Manifest of Underground FacilityLocate Operation;”

U.S. publication no. 2009-0204466-A1, published Aug. 13, 2009, filedSep. 4, 2008, and entitled “Ticket Approval System For and Method ofPerforming Quality Control In Field Service Applications;”

U.S. publication no. 2009-0207019-A1, published Aug. 20, 2009, filedApr. 30, 2009, and entitled “Ticket Approval System For and Method ofPerforming Quality Control In Field Service Applications;”

U.S. publication no. 2009-0210284-A1, published Aug. 20, 2009, filedApr. 30, 2009, and entitled “Ticket Approval System For and Method ofPerforming Quality Control In Field Service Applications;”

U.S. publication no. 2009-0210297-A1, published Aug. 20, 2009, filedApr. 30, 2009, and entitled “Ticket Approval System For and Method ofPerforming Quality Control In Field Service Applications;”

U.S. publication no. 2009-0210298-A1, published Aug. 20, 2009, filedApr. 30, 2009, and entitled “Ticket Approval System For and Method ofPerforming Quality Control In Field Service Applications;”

U.S. publication no. 2009-0210285-A1, published Aug. 20, 2009, filedApr. 30, 2009, and entitled “Ticket Approval System For and Method ofPerforming Quality Control In Field Service Applications;”

U.S. publication no. 2009-0324815-A1, published Dec. 31, 2009, filedApr. 24, 2009, and entitled “Marking Apparatus and Marking Methods UsingMarking Dispenser with Machine-Readable ID Mechanism;”

U.S. publication no. 2010-0006667-A1, published January 14, 2010, filedApr. 24, 2009, and entitled, “Marker Detection Mechanisms for use inMarking Devices And Methods of Using Same;”

U.S. publication no. 2009-0204238-A1, published Aug. 13, 2009, filedFeb. 2, 2009, and entitled “Electronically Controlled Marking Apparatusand Methods;”

U.S. publication no. 2009-0208642-A1, published Aug. 20, 2009, filedFeb. 2, 2009, and entitled “Marking Apparatus and Methods For Creatingan Electronic Record of Marking Operations;”

U.S. publication no. 2009-0210098-A1, published Aug. 20, 2009, filedFeb. 2, 2009, and entitled “Marking Apparatus and Methods For Creatingan Electronic Record of Marking Apparatus Operations;”

U.S. publication no. 2009-0201178-A1, published Aug. 13, 2009, filedFeb. 2, 2009, and entitled “Methods For Evaluating Operation of MarkingApparatus;”

U.S. publication no. 2009-0238417-A1, published Sep. 24, 2009, filedFeb. 6, 2009, and entitled “Virtual White Lines for Indicating PlannedExcavation Sites on Electronic Images;”

U.S. publication no. 2009-0202112-A1, published Aug. 13, 2009, filedFeb. 11, 2009, and entitled “Searchable Electronic Records ofUnderground Facility Locate Marking Operations;”

U.S. publication no. 2009-0204614-A1, published Aug. 13, 2009, filedFeb. 11, 2009, and entitled “Searchable Electronic Records ofUnderground Facility Locate Marking Operations;”

U.S. publication no. 2009-0327024-A1, published Dec. 31, 2009, filedJun. 26, 2009, and entitled “Methods and Apparatus for QualityAssessment of a Field Service Operation;”

U.S. publication no. 2010-0010862-A1, published January 14, 2010, filedAug. 7, 2009, and entitled, “Methods and Apparatus for QualityAssessment of a Field Service Operation Based on GeographicInformation;”

U.S. publication No. 2010-0010863-A1, published January 14, 2010, filedAug. 7, 2009, and entitled, “Methods and Apparatus for QualityAssessment of a Field Service Operation Based on Multiple ScoringCategories;”

U.S. publication no. 2010-0010882-A1, published January 14, 2010, filedAug. 7, 2009, and entitled, “Methods and Apparatus for QualityAssessment of a Field Service Operation Based on Dynamic AssessmentParameters;” and

U.S. publication no. 2010-0010883-A1, published January 14, 2010, filedAug. 7, 2009, and entitled, “Methods and Apparatus for QualityAssessment of a Field Service Operation Based on Multiple QualityAssessment Criteria.”

It should be appreciated that all combinations of the foregoing conceptsand additional concepts discussed in greater detail below (provided suchconcepts are not mutually inconsistent) are contemplated as being partof the inventive subject matter disclosed herein. In particular, allcombinations of claimed subject matter appearing at the end of thisdisclosure are contemplated as being part of the inventive subjectmatter disclosed herein. It should also be appreciated that terminologyexplicitly employed herein that also may appear in any disclosureincorporated by reference should be accorded a meaning most consistentwith the particular concepts disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example in which a locate and marking operation isinitiated as a result of an excavator providing an excavation notice toa one-call center;

FIG. 2 illustrates one example of a conventional locate instrument setincluding a locate transmitter and a locate receiver;

FIGS. 3A and 3B illustrate a conventional marking device in an actuatedand non-actuated state, respectively;

FIG. 4 is a functional block diagram of a data acquisition systemincluding a locate device for creating electronic records of locateoperations and displaying facilities map information, according to someembodiments of the present invention;

FIG. 5 is a perspective view of the data acquisition system of FIG. 4,illustrating an exemplary locate device upon which some embodiments ofthe invention may be implemented;

FIG. 6 is a flow diagram of an exemplary method for collecting locateinformation for generation of an electronic record, according to oneembodiment of the present invention;

FIG. 7 is a block diagram of an exemplary data structure for anelectronic record of a locate operation including information retrievedduring one or more actuations of a locate receiver, according to oneembodiment of the present invention;

FIG. 8 is a flow diagram of an exemplary method for operating a locatedevice having a locate mode and a landmark mode so as to collect locateinformation and/or environmental landmark information, and generate anelectronic record of such information, according to one embodiment ofthe present invention;

FIG. 9 is a block diagram of an exemplary data structure for anelectronic record of a locate operation including both locateinformation and landmark information retrieved during actuations of alocate device, according to one embodiment of the present invention;

FIG. 10 is a flow diagram of an exemplary method for displaying a visualrepresentation of a locate operation in a display field having apredetermined scale, according to one embodiment of the presentinvention;

FIG. 11 is an example of a visual representation showing electronicdetection marks and identifiers for environmental landmarks based ondata collected by a locate receiver during a locate operation, accordingto one embodiment of the present invention;

FIG. 12 is an example of another visual representation of locateoperations, according to one embodiment of the present invention;

FIG. 13 is an example of another visual representation of a locateoperation, according to another embodiment of the present invention, inwhich electronic detection marks and identifiers for environmentallandmarks are overlaid on a digital image of a work site/dig area;

FIG. 14 shows a generic display device having a display field in whichone or more display layers and/or sub-layers of locate information,landmark information and/or image/reference information may beselectively enabled or disabled for display, according to one embodimentof the present invention;

FIG. 15 is a functional block diagram of a data acquisition systemincluding a locate receiver with both environmental sensors andoperational sensors, according to one embodiment of the presentinvention;

FIG. 16 is a block diagram showing details of the environmental sensorsshown in FIG. 15, according to one embodiment of the present invention;

FIG. 17 is a block diagram showing details of the operational sensorsshown in FIG. 15, according to one embodiment of the present invention;

FIG. 18 is a block diagram of an exemplary data structure of anelectronic record of a locate operation including information receivedfrom environmental sensors and operational sensors of the locatereceiver, according to one embodiment of the present invention;

FIG. 19 illustrates a functional block diagram of an example of anoperations monitoring application for monitoring the use of locatingequipment such as a locate receiver, according to one embodiment of thepresent invention;

FIG. 20 illustrates a functional block diagram of an example of a locateoperations system including the operations monitoring application ofFIG. 19, according to one embodiment of the present invention;

FIG. 21 illustrates a method of operation of a locate operations systemincluding an operations monitoring application, according to oneembodiment of the present invention;

FIG. 22 is a schematic diagram illustrating a configuration fordetermining the difference in location between two points of a locatereceiver;

FIG. 23 illustrates a pattern of motion of a locate receiver, accordingto various of the embodiments described herein;

FIG. 24 illustrates a portion of a locate receiver including tactileindicators, according to one embodiment of the present invention;

FIG. 25 illustrates a locate transmitter including a tactile indicator,according to one embodiment of the present invention;

FIG. 26 is a functional block diagram of a data acquisition systemincluding a locate transmitter with both environmental sensors andoperational sensors, according to one embodiment of the presentinvention;

FIG. 27 illustrates a locate transmitter including a ground probe fordetecting one or more characteristics of a material into which it isinserted.

DETAILED DESCRIPTION

Following below are more detailed descriptions of various conceptsrelated to, and embodiments of, inventive locate apparatus havingenhanced features for underground facility locate operations, andassociated methods and systems. It should be appreciated that variousconcepts introduced above and discussed in greater detail below may beimplemented in any of numerous ways, as the disclosed concepts are notlimited to any particular manner of implementation. Examples of specificimplementations and applications are provided primarily for illustrativepurposes.

I. Overview

In some embodiments of the present invention, a locate device employedby a locate technician to detect or infer a presence or an absence ofone or more underground facilities is particularly configured to acquire“locate information” relating to a locate operation, and create anelectronic record of at least some of the locate information. Asdiscussed in greater detail below, examples of locate informationrelating to the locate operation that may be logged into an electronicrecord may include, but are not limited to, any of the following typesof information or any suitable combinations of such information:

-   -   timing information (e.g., one or more time stamps) associated        with one or more events occurring during a given locate        operation;    -   geographic information (e.g., one or more geographic        coordinates) associated with one or more events of a locate        operation (in some instances, the geographic information may be        accompanied by timing information, such as a time stamp, for        each acquisition of geographic information); and/or geographic        diagnostics information (e.g., GPS diagnostics information, such        as, but not limited to, the quality of a GPS signal, the number        of satellites in view of the GPS receiver, etc.);    -   service-related information: one or more identifiers for the        locate technician performing the locate operation, the locate        contractor (service provider) dispatching the locate technician,        and/or the party requesting the locate operation;    -   ticket information: information relating to one or more        facilities to be located, location information (e.g., an        address, geo-coordinates, and/or text description) relating to        the work site and/or dig area in which the locate and marking        operation is performed, ground type information (e.g., a        description of the ground at which the locate is performed),        excavator information, other text-based information, etc.    -   target object information: information about the target object        (e.g., facility) to be located, such as the type of object,        expected depth of object, etc.;    -   locate signal information: information entered, detected and/or        sensed as part of performing the locate operation relating to        one or more signals representing a presence or absence of one or        more underground facilities, such as magnetic field strength and        frequency, electric current magnitude, depth of the located        object, the mode of operation of the locate receiver (e.g.,        peak v. null detection modes), the gain of the locate receiver,        etc. With respect to locate receivers, the “gain” is typically a        measure of the degree of sensitivity of a locate receiver        antenna that is picking up a signal emanating from along an        underground facility (alternatively, “gain” may be viewed as a        degree of amplification being applied to a received signal).        Gain may be expressed in terms of any scale (e.g., 0-100), as a        numeric value or percentage. “Signal strength” (or “magnetic        field strength”) refers to the strength of a received signal at        a given gain value; signal strength similarly may be expressed        in terms of any scale, as a numeric value or percentage.        Generally speaking, higher signal strengths at lower gains        typically indicate more reliable information from a locate        receiver, but this may not necessarily be the case for all        locate operations;    -   locate receiver information: information about the locate        receiver, such as identification of the locate receiver (e.g.,        serial number), make and model of the locate receiver, mode of        operation (e.g., passive or active, and peak or null), battery        level, etc.;    -   transmitter information: information about any transmitter and        transmitter signal (also referred to herein as an applied        signal) utilized for the locate operation, such as transmitter        type, identification of the transmitter (e.g., serial number),        make and model of the transmitter, mode of operation (e.g.,        inductive and conductive), battery level, connection type,        electrical ground type, electrical ground position, moisture        content of physical ground to which electrical ground contact is        made, pH of physical ground, applied signal frequency, available        signal frequencies, transmitter power, whether a continuity        indication is provided for the applied signal, etc.;    -   tracer wire information: information about a tracer wire        provided along the underground facility, such as tracer wire        material (e.g., aluminum, tin/steel, copper/stainless steel,        etc.), gauge of the tracer wire, condition of the tracer wire        (e.g., whether intact, broken, corroded, etc.), etc.;    -   environmental information: information derived from one or more        environmental sensors associated with the locate device,        examples of which sensors include, but are not limited to,        temperature sensors, humidity sensors, light sensors, altitude        sensors, image capture devices and audio recorders, as well as        information that may be manually entered (e.g., by a technician)        relating to environmental conditions (e.g., ground type in the        area of the locate operation, which could also or alternatively        be indicated in ticket information);    -   operational information: information derived from one or more        operational sensors associated with the locate device, examples        of which sensors include, but are not limited to, operational        temperature sensors, a compass, an inclinometer, one or more        accelerometers, a yaw rate sensor, a proximity sensor, a        pressure sensor, one or more device health sensors, image        capture devices, and audio devices; and    -   Device health information: information about the status of one        or more components of a locate device, such as battery status,        WiFi connectivity status, GPS receiver status (e.g., GPS signal        strength/quality, number of satellites in view), etc.

Locate information including any or all of the foregoing types ofinformation may be logged/stored in local memory of a locate device,formatted in various manners, processed and/or analyzed at the locatedevice itself, and/or transmitted to another device (e.g., a remotecomputer/server) for storage, processing and/or analysis. In particular,environmental and/or operational information may be used to controloperation of the locate device, assess out-of-tolerance conditions inconnection with use of the locate device, and/or provide alerts or otherfeedback. In yet other embodiments, operational information may beanalyzed and processed so as to improve a determination of a location(e.g., GPS coordinates) of a detecting tip of the locate device (e.g., aportion of the locate device close to the ground, pavement or othersurface below which one or more underground facilities may be disposed)during use.

In other embodiments, a locate device may be configured to operate inmultiple different modes so as to collect various information relatingnot only to a locate operation itself, but additionally (oralternatively) various information relating to the work site/dig area inwhich the locate operation is performed. For example, in oneimplementation, the locate device may be configured to operate in afirst “locate mode” as well as a second “landmark identification mode”(or more simply “landmark mode”). In a “locate mode,” variousfunctionality may be enabled relating to the detection of a presence orabsence of an underground facility. Alternatively, in a “landmark mode,”a technician positions the locate device proximate to an environmentallandmark of interest and the locate device collects various informationabout the landmark (hereafter referred to as “landmark information”). Asdiscussed in greater detail below, landmark information may include, butis not limited to, geo-location data of an environmental landmark, typeof environmental landmark, and a time stamp for any acquired informationrelating to an environmental landmark.

In other embodiments, a locate device may be operated in a “solo” modeor a “group” mode. In particular, in a “solo” mode, the locate devicemay be operated as an individual, independent device to collect, storeand/or transmit data, whereas in “group” mode, a locate device may actas a “worker” device or a “leader” device to facilitate consolidation ofdata collected by multiple devices (e.g., relating to a same ticket) toa host server.

In yet other embodiments, a locate device may be equipped with anenhanced user interface having tactile functionality; in particular, thelocate device may include one or more tactile indicators (e.g.,vibrating devices) disposed, for example, in a handle, joy stick,actuator or elsewhere on the device, to provide a tactile indication toa technician using the locate device (e.g., as feedback in connectionwith an operating mode, operating condition, environmental condition,etc.).

In various implementations of the methods and apparatus describedherein, data from one or more electronic records, including one or morepieces of locate information and/or one or more pieces of landmarkinformation, may be processed and analyzed to provide insight into thelocate operation. In one embodiment, a computer-generated image or othervisual representation based on the locate information and/or landmarkinformation may be electronically rendered; for example, this visualrepresentation may provide electronic indications (“electronic detectionmarks”) of the relative location of detected underground facilitiesduring a locate operation, and electronic detection marks correspondingto different types of facilities may be color-coded. Additionally,electronic identifiers (e.g., icons, shapes, symbols, patterns, etc.) ofone or more environmental landmarks may be included in a visualrepresentation, alone or together with electronic detection marks. Sucha visual representation may be used, for example, to provide immediatefeedback to the locate technician (e.g., via a display device associatedwith the locate device), provide essentially real-time feedback to asupervisor monitoring the technician's work from a remote location,provide a visual record of the locate information and/or landmarkinformation (e.g., for archiving purposes once one or more electronicrecords are generated), and/or to verify the quality (e.g., accuracy andcompleteness) of work performed during a locate and marking operation.

II. Locate Device

As discussed above, a locate device may refer to either a locatetransmitter or a locate receiver. In one embodiment of the presentinvention, one or both of a locate transmitter and a locate receiver maybe particularly configured to acquire locate information relating to alocate operation, generate an electronic record of the acquired locateinformation, and store, transmit, analyze or otherwise process theacquired locate information. While a detailed illustrative embodiment isdescribed below using the example of a locate receiver, it should beappreciated that the various inventive concepts disclosed herein inconnection with enhanced features for locate receivers may be appliedsimilarly, if not identically in some instances, to locate transmittersas well.

Various types of locate information may be generated during, orotherwise associated with, the use of a locate device (e.g., a locatereceiver or a locate transmitter) or a locate set to perform a locateoperation. Exemplary categories of locate information were providedabove as an overview; however, it should be appreciated that theseexemplary categories are provided primarily for purposes ofillustration, and that locate information is not limited according tovarious embodiments discussed herein to the particular exemplarycategories and types of information outlined above.

In general, locate information related to the use of the transmitter mayinclude, but is not limited to, information about the applied signalpower, the applied signal frequency, the possible or available signalfrequencies (e.g., if the locate transmitter has more than one frequencyavailable), the presence, magnitude, and type of noise (e.g.,distortion) on the applied signal (e.g., a signal-to-noise ratio), thelocation of the transmitter, the mode of operation (e.g., conductive orinductive) and therefore the manner in which connection is made to thetarget object (e.g., direct connection or inductive clamp), anidentification of the transmitter unit (e.g., serial number), make andmodel of the transmitter unit, information about how the transmitterunit is grounded (if at all), and an indication of whether a sufficientelectrical connection has been made to the target object (e.g., sometransmitters produce a “continuity signal” indicative of the quality ofthe connection between the transmitter and the target object). Locateinformation related to the use of the locate receiver may include, butis not limited to, an identification of the locate receiver (e.g., aserial number), the mode of operation of the locate receiver (e.g., peakmode v. null mode, as well as active v. passive mode), the frequency towhich the locate receiver is tuned, the gain of the locate receiver, thefrequency of a detected magnetic field, the amplitude/strength of adetected magnetic field, the electrical current of the detected signal,the location of the locate receiver, and a depth measurement taken bythe locate receiver (which may be used, for example, as additionalinformation regarding a target object). In addition, locate informationrelating to the locate operation itself may include, but is not limitedto, information about the target object, the location of the locatesite, the party requesting the locate, the party performing the locate,and whether any locate operations have previously been performed forthis site.

Information about a tracer wire may also be included in locateinformation. For example, information about the material of a tracerwire may be collected (e.g., input verbally or textually by atechnician), which may indicate a type of underground facility (e.g.,aluminum may indicate cable, tin/steel may indicate phone, andcopper/stainless steel may indicate gas, among others). The wire gaugeof the tracer wire, as well as the condition of the tracer wire (e.g.,intact, corroded, etc.) may also be visually determined by a locatetechnician and recorded verbally, textually, or in any other manner.Moreover, whether the tracer wire is broken may be visually detected andnoted as part of locate information. Similarly, whether a service lineis properly bonded to a main may be useful locate information.Furthermore, information about the type of sheathing for the tracer wiremay be included as part of locate information. Other types ofinformation may also be considered locate information, as these arenon-limiting examples.

According to some aspects of the invention, locate information relatingto a locate set, and/or locate operation more generally, may begenerated, recorded, transmitted, and/or processed, for example, toenable evaluation of the performance of the locate technician,evaluation of the operation of the locate equipment, reconstruction ofthe actions taken by the locate technician during the locate operation,and/or to facilitate comparison of collected data to historical data.

In one exemplary embodiment, a locate receiver is configured to storeand/or transmit locate information relating to a locate set and/or alocate operation, and in some implementations generate an electronicrecord of at least some of the locate information. FIGS. 4 and 5illustrate a functional block diagram and perspective view,respectively, of one example of a data acquisition system 100, includinga locate device such as a locate receiver 110 and optionally a remotecomputer 150, according to one embodiment of the present invention. Oneor both of the locate receiver 110 and the remote computer 150 of thedata acquisition system 100 may be configured to collect locateinformation relating to performance of a locate operation.

As shown in FIG. 4, in one embodiment locate receiver 110 includescontrol electronics 112, the components of which are powered by a powersource 114. Power source 114 may be any power source that is suitablefor use in a portable device, such as, but not limited to, one or morerechargeable batteries, one or more non-rechargeable batteries, a solarphotovoltaic panel, a standard AC power plug feeding an AC-to-DCconverter, and the like.

As also shown in FIG. 4, in one embodiment control electronics 112 oflocate receiver 110 may include, but are not limited to, a processor118, at least a portion of an actuation system 120 (another portion ofwhich may include one or more mechanical elements), a local memory 122,a communication interface 124, a user interface 126, a timing system128, and a location tracking system 130.

The processor 118 may be any general-purpose processor, controller, ormicrocontroller device. Local memory 122 may be any volatile ornon-volatile data storage device, such as, but not limited to, a randomaccess memory (RAM) device and a removable memory device (e.g., auniversal serial bus (USB) flash drive, a multimedia card (MMC), asecure digital card (SD), a compact flash card (CF), etc.). As discussedfurther below, the local memory may store a locate data algorithm 137,which may be a set of processor-executable instructions that whenexecuted by the processor 118 causes the processor to control variousother components of the locate receiver 110 so as to generate anelectronic record 135 of a locate operation, which record also may bestored in the local memory 122 and/or transmitted in essentiallyreal-time (as it is being generated) or after completion of a locateoperation to a remote device (e.g., remote computer 150).

In one exemplary implementation, a Linux-based processing system forembedded handheld and/or wireless devices may be employed in the locatereceiver 110 to implement various components of the control electronics112. For example, the Fingertip4™ processing system, including a MarvellPXA270 processor and available from InHand Electronics, Inc.(www.inhandelectronics.com/products/fingertip4), may be used. Inaddition to the PXA270 processor (e.g., serving as the processor 118),the Fingertip4™ includes flash memory and SDRAM (e.g., serving as localmemory 122), multiple serial ports, a USB port, and other I/O interfaces(e.g., to facilitate interfacing with one or more input devices andother components of the locate receiver), supports a variety of wiredand wireless interfaces (WiFi, Bluetooth®, GPS, Ethernet, any IEEE802.11 interface, or any other suitable wireless interface) tofacilitate implementation of the communication interface 124, andconnects to a wide variety of LCD displays (to facilitate implementationof a user interface/display). In yet other exemplary implementations,the processor 118 may be realized by multiple processors thatdivide/share some or all of the functionality discussed herein inconnection with the processor 118. For example, in one implementation,an Atom™ processor available from Intel Corporation of Santa Clara,Calif., may be used alone or in connection with one or more PICprocessors to accomplish various functionality described herein.

Communication interface 124 of locate receiver 110 may be any wiredand/or wireless communication interface by which information may beexchanged between locate receiver 110 and an external or remote device,such as a remote computing device that is elsewhere in the dig area(i.e., not a part of the locate receiver 110) or outside the dig area.For example, data that is provided by components of data acquisitionsystem 100 and/or stored in local memory 122 (e.g., one or moreelectronic records 135) may be transmitted via communication interface124 to a remote computer, such as remote computer 150, for processing.Examples of wired communication interfaces may include, but are notlimited to, USB ports, RS232 connectors, RJ45 connectors, Ethernet, andany combination thereof. Examples of wireless communication interfacesmay include, but are not limited to, an Intranet connection, Internet,Bluetooth® technology, Wi-Fi, Wi-Max, IEEE 802.11 technology (e.g.,operating at a minimum bandwidth of 54 Mbps, or any other suitablebandwidth), radio frequency (RF), Infrared Data Association (IrDA)compatible protocols, Local Area Networks (LAN), Wide Area Networks(WAN), Shared Wireless Access Protocol (SWAP), any combination thereof,and other types of wireless networking protocols. The wireless interfacemay be capable of capturing signals that reflect a user's intent. Forexample, the wireless interface may include a microphone that cancapture a user's intent by capturing the user's audible commands.Alternatively, the wireless interface may interact with a device thatmonitors a condition of the user, such as eye movement, brain activity,and/or heart rate.

User interface 126 of locate receiver 110 may be any mechanism orcombination of mechanisms by which a user may operate data acquisitionsystem 100 and by which information that is generated by dataacquisition system 100 may be presented to the user. For example, userinterface 126 may include, but is not limited to, a display device(including integrated displays and external displays, such as Heads-UpDisplays (HUDs)), a touch screen, one or more manual pushbuttons, amicrophone to provide for audible commands, one or more light-emittingdiode (LED) indicators, one or more toggle switches, a keypad, an audiooutput (e.g., speaker, buzzer, and alarm), and any combination thereof.In one implementation, the user interface 126 includes a “menu/on”button to power up the locate receiver and provide a menu-drivengraphical user interface (GUI) displayed by the display device (e.g.,menu items and/or icons displayed on the display device) and navigatedby the technician via a joystick or a set of four “up/down/left/right”buttons, as well as a “select/ok” button to take some action pursuant tothe selection of a menu item/icon. As described below, the display mayalso be used in some embodiments of the invention to display variousimages germane to a locate and/or marking information, as well asinformation relating to a placement of marking material in a dig area, alocation of an underground facility in a dig area, or any other suitableinformation that may be displayed based on information acquired tocreate an electronic record 135.

In various embodiments, the one or more interfaces of the locatereceiver 110—including the communication interface 124 and userinterface 126—may be used as input devices to receive information to bestored in the memory 122, to facilitate various functions of the locatereceiver and/or to be logged as part of an electronic record of a locateoperation. In some cases, locate information received via theinterface(s) (e.g., via the communication interface 124) may includeticket information regarding underground facilities to be detectedduring a locate operation. As another example, using an interface suchas the user interface 126, service-related information may be input,including an identifier for the locate receiver used by the technician,an identifier for a technician, and/or an identifier for thetechnician's employer. Alternatively, some or all of the service-relatedinformation similarly may be received via the communication interface124 (and likewise some or all of the ticket information may be receivedvia the user interface 126). As also noted above, various imageinformation also may be received via the communication interface 124.

The actuation system 120 of locate receiver 110 shown in the blockdiagram of FIG. 4 may include both electrical and mechanical elementsaccording to various embodiments, and for purposes of illustration isshown in FIG. 4 as included as part of the control electronics 112. Theactuation system 120 may include a mechanical and/or electrical actuatormechanism (e.g., see the actuator 142 shown in FIG. 5) to provide one ormore signals or stimuli as an input to the actuation system 120. Uponreceiving one or more signals or stimuli (e.g., actuation/triggering bya locate technician or other user), the actuation system 120 may causethe logging of various data constituting locate information. To thisend, the actuation system 120 may provide one or more output signals inthe form of an actuation signal 121 to the processor 118 to indicate oneor more actuations of the locate receiver, in response to which theprocessor 118 may acquire/collect various locate information and logdata into the electronic record 135.

Location tracking system 130 of locate receiver 110 constitutes anothertype of input device that provides locate information, and may includeany device that can determine its geographical location to a certaindegree of accuracy. For example, location tracking system 130 mayinclude a global positioning system (GPS) receiver or a globalnavigation satellite system (GNSS) receiver. A GPS receiver may provide,for example, any standard format data stream, such as a National MarineElectronics Association (NMEA) data stream, or other data formats. Anerror correction component may be, but is not limited to, any mechanismfor improving the accuracy of the geographic information provided bylocation tracking system 130; for example, an error correction componentmay be an algorithm for correcting any offsets (e.g., due to localdisturbances in the atmosphere) in the geo-location data of locationtracking system 130. An error correction component may reside at thelocation tracking system 130 or a remote computing device, such asremote computer 150. In other embodiments, location tracking system 130may include any device or mechanism that may determine location by anyother means, such as performing triangulation by use of cellularradiotelephone towers.

In one exemplary implementation, the location tracking system 130 mayinclude an ISM300F2-05-V0005 GPS module available from Inventek Systems,LLC of Westford, Mass. (seewww.inventeksys.com/html/ism300f2-c5-v0005.html). The Inventek GPSmodule includes two UARTs (universal asynchronous receiver/transmitter)for communication with the processor 118, supports both the SIRF Binaryand NMEA-0183 protocols (depending on firmware selection), and has aninformation update rate of 5 Hz. A variety of geographic locationinformation may be requested by the processor 118 and provided by theGPS module to the processor 118 including, but not limited to, time(coordinated universal time—UTC), date, latitude, north/south indicator,longitude, east/west indicator, number and identification of satellitesused in the position solution, number and identification of GPSsatellites in view and their elevation, azimuth and SNR values, anddilution of precision values. Accordingly, it should be appreciated thatin some implementations the location tracking system 130 may provide awide variety of geographic information as well as timing information(e.g., one or more time stamps) to the processor 118.

In another embodiment, location tracking system 130 may not residelocally on locate receiver 110. Instead, location tracking system 130may reside on any on-site computer, which serves as a location referencepoint, to which the location of locate receiver 110 may be correlated byany other means, such as, but not limited to, by a triangulationtechnique between the on-site computer and locate receiver 110.

With respect to other input devices of the locate receiver 110 that mayprovide locate information, the control electronics 112 may also includea timing system 128 having an internal clock (not shown), such as acrystal oscillator device, for processor 118. Additionally, timingsystem 128 may include a mechanism for registering time with a certaindegree of accuracy (e.g., accuracy to the minute, second, ormillisecond) and may also include a mechanism for registering thecalendar date. In various implementations, the timing system 128 may becapable of registering the time and date using its internal clock, oralternatively timing system 128 may receive its time and dateinformation from the location tracking system 130 (e.g., a GPS system)or from an external timing system, such as a remote computer or network,via communication interface 124. In yet other implementations, adedicated timing system for providing timing information to be logged inan electronic record 135 may be optional, and timing information forlogging into an electronic record may be obtained from the locationtracking system 130 (e.g., GPS latitude and longitude coordinates with acorresponding time stamp). Timing information may include, but is notlimited to, a period of time, timestamp information, date, and/orelapsed time.

As shown in FIGS. 4 and 5, the locate receiver 110 further includesdetection electronics 131, which provides another example of an inputdevice that may provide location information to the processor 118. Inexemplary implementations, the detection electronics 131 in turnincludes an RF antenna 127, a detection circuit 139, and a processingcircuit 133. Each of these components is explained in greater detailfurther below.

In one embodiment, information provided by one or more input devices ofthe locate receiver 110 (e.g., the timing system 128, the locationtracking system 130, the detection electronics 131, the user interface126, the communication interface 124) is acquired and logged (stored inmemory) upon actuation of the actuation system 120 (e.g., triggering anactuator). Some embodiments of the invention may additionally oralternatively acquire/log information from one or more input devices atone or more times during or throughout an actuation, such as when atechnician is holding a mechanical or electrical actuator for someperiod of time and moving to detect a presence of an undergroundfacility. In various aspects of such embodiments, locate informationderived from one or more input devices may be collected at a start timeof an actuation, at one or more times during an actuation, and in somecases at regular intervals during an actuation (e.g., several times persecond, once per second, once every few seconds). Further, some locateinformation may be collected at an end of an actuation, such as timeinformation that may indicate a duration of an actuation.

Additionally, it should be appreciated that while some locateinformation may be received via one or more input devices at the startof each locate operation and upon successive actuations of the locatereceiver, in other cases some locate information, as well as facilitiesmaps information and/or other image information, may be collected by orprovided to the locate receiver prior to a locate operation (e.g., onpower-up or reset of the locate receiver, as part of an electronicinstruction or dispatch by a locate company, and/or in response to arequest/query from a locate technician), and stored in local memory 122for subsequent use by the locate receiver (e.g., display of informationvia the user interface display 146, later incorporation into anelectronic record, etc.). For example, prior to a given locate operationand one or more actuations of the locate receiver, one or more of ticketinformation, service-related information, and image information, mayhave already been received (e.g., via the communication interface 124and/or user interface 126) and stored in local memory 122. Pursuant to alocate operation (e.g., immediately before, during and/or after a locateoperation), information previously received via the interface(s) may beretrieved from the local memory (if stored there initially), anddisplayed and/or entered into an electronic record as appropriate, insome case together with information collected pursuant to one or moreactuations of the locate receiver. In some implementations, ticketinformation and/or service-related information may be received via theinterface(s) and stored in an entry in the electronic record 135“directly” in response to one or more actuations of the locate receiver(e.g., without being first stored in local memory).

In sum, according to embodiments of the present invention, variouslocate information from one or more input devices, as well as imageinformation, regardless of how or when it is received, may be displayedin various manners and/or stored in memory of the locate receiver (e.g.,in an electronic record of a locate operation), and in someimplementations at least some of the locate information may be loggedpursuant to one or more actuations of the locate receiver.

In various implementations, the optional remote computer 150 of the dataacquisition system 100 may be any external computer system with whichthe locate receiver 110 communicates (e.g., via the communicationsinterface 124). In one embodiment, the remote computer 150 may be acentralized computer, such as a central server of an undergroundfacility locate service provider. In another embodiment, remote computer150 may be a computer that is at or near the work site (i.e.,“on-site”), e.g., a computer that is present in a locate technician'svehicle. The remote computer may also or alternatively store one or moreof the electronic record 135, the locate data algorithm 137 and one ormore images.

According to one embodiment, the remote computer may form part of adocking station in which a locate device (e.g., a locate receiver orlocate transmitter) may be docked, for example when not in use. Thedocking station may be mechanically and electrically coupled to thelocate device. For example, the docking station may provide mechanicalsupport via a clip, a clamp, a strap, or other mechanical device forholding the locate device in place. The docking station may also provideelectrical interconnection to the locate device, via which the powersupply of the locate device may be charged and/or data may betransferred. Suitable docking stations are described in U.S. patentapplication Ser. No. 12/571,411, filed Sep. 30, 2009 under AttorneyDocket No. D0687.70009US01 and entitled “Marking Device Docking Stationsand Methods of Using Same”, which is hereby incorporated herein byreference in its entirety. Docking stations according to the conceptsdescribed therein may also be applicable to the locate devices describedherein. According to one embodiment, a locate receiver may communicatewith the docking station via communication interface 124, although otherconfigurations are possible.

Docking events (e.g., docking and de-docking of a locate receiver) maybe recorded as event entries, for example similar in form to the evententries of Tables 2-5, discussed in detail below. Table 1A illustratesan example of event entry indicating a change in docking status of alocate receiver. Other entry formats are also possible.

TABLE 1A Format INFO+DOCK: (DATE) (TIME) (GPS data) (DOCKING STATE)<CR><LF> Examples INFO+ DOCK R: DATE(2009-04-15) TIME(12:04:44)GPS($GPGGA,120443,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )DOCK(DOCKED)<CR><LF> INFO+ DOCK: DATE(2009-04-15) TIME(12:04:45)GPS($GPGGA,120445,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )DOCK(DE-DOCKED)<CR><LF> INFO+ DOCK: DATE(2009-04-15) TIME(12:04:46)GPS($GPGGA,120446,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )DOCK(DOCKED)<CR><LF>

Whether resident and/or executed on either the locate device 110 or theremote computer 150, as noted above the locate data algorithm 137includes a set of processor-executable instructions (e.g., stored inmemory, such as local memory 122 of the locate device) that, whenexecuted by processor 118 of the locate device 110 or another processor,processes information (e.g., various locate information) collected inconnection with a locate operation. Locate data algorithm 137, whenexecuted by the processor 118, may cause the processor to performcollection, logging/storage (creation of electronic records), and insome instances further processing and analysis of various locateinformation. For example, as discussed in further detail below, theoperations of locate data algorithm 137 as effected by the processor 118may include, but are not limited to, the following:

-   -   (1) reading in (acquiring) data that is generated by any        component (e.g., one or more input devices);    -   (2) processing the information that is collected and, in some        instances, associating the collected information with respective        actuations of an actuator (e.g., if the locate device is        operated in a manual or semi-automatic mode based on actuation,        as discussed further below); for example, any information        collected may be parsed/packaged so as to be associated with any        one or more actuations of the locate device, irrespective of        when the data was actually acquired;    -   (3) formatting the acquired information, e.g., as multiple        time-stamped event entries, which in some instances may        constitute actuation data sets forming an electronic record,        wherein each actuation data set corresponds to a particular        actuation; and    -   (4) using respective entries of an electronic record to visually        recreate the locate operation (e.g., render a computer-generated        representation in a display field, wherein respective entries        correspond to electronic detection marks).

It should also be appreciated that, in some embodiments, the locate dataalgorithm 137 may include one or more adjustable parameters that governvarious aspects of the collection and logging of locate information(e.g., the rate at which various locate information is collected fromone or more input devices), and that these parameters may be adjusted orset, for example, by an administrator at a remote computer, after whichthe locate data algorithm is downloaded to the locate device forexecution by the processor 118. Alternatively, in other implementations,adjustable parameters of a locate data algorithm already resident on alocate device may in some cases be adjusted remotely via thecommunication interface, or locally via the user interface.

While the functionality of various components of the locate receiver 110was discussed above in connection with FIG. 4, FIG. 5 shows somestructural aspects of the locate receiver 110 according to oneembodiment. For example, the locate receiver 110 may include anelongated housing 136 in which is disposed one or more elements of theactuation system 120, one or more elements of the control electronics112 and the power source 114. Elongated housing 136 may be hollow or maycontain certain cavities or molded compartments for installing anycomponents therein, such as the various components of locate receiver110 that are shown in FIG. 4. The elongated housing 136 and otherstructural elements associated with the housing, as discussed below, maybe formed of any rigid, semi-rigid, strong, and lightweight material,such as, but not limited to, molded plastic and aluminum.

Incorporated at a proximal end of elongated housing 136 may be a handle138, which provides a convenient grip by which the user (e.g., thelocate technician) may carry the locate receiver 110 during use (i.e.,the exemplary locate receiver depicted in FIG. 5 is intended to be ahand-held device). In one implementation, the power source 114 may beprovided in the form of a removable battery pack housing one or morerechargeable batteries that are connected in series or parallel in orderto provide a DC voltage to locate receiver 110, and disposed within acompartment in the handle 138. Such an arrangement facilitates use ofconventional removable/rechargeable battery packs often employed in avariety of cordless power tools, in which the battery pack similarly issituated in a handle of the tool. It should be appreciated, however,that the power source 114 in the form of a battery pack may be disposedin any of a variety of locations within or coupled to the elongatedhousing 136.

As also shown in FIG. 5, mounted near handle 138 is user interface 126,which may include a display 146. The display 146 may be a touch screendisplay to facilitate interaction with a user/technician, and/or theuser interface also may include one or more buttons, switches,joysticks, a keyboard, and the like to facilitate entry of informationby a user/technician. One or more elements of the control electronics112 (e.g., the processor 118, memory 122, communication interface 124,and timing system 128) also may be located in the proximal end of theelongated housing in the vicinity of the user interface 126 and display146. As with the power source 114, it should be appreciated that one ormore elements of the control electronics 112 may be disposed in any of avariety of locations within or coupled to the elongated housing 136.

In the embodiment of FIG. 5, the location tracking system 130 similarlymay be positioned on the proximal end of the elongated housing 136 tofacilitate substantially unobstructed exposure to the atmosphere; inparticular, as illustrated in FIG. 5, the location tracking system 130may be situated on a ground plane 138 (providing an electrical ground atleast at the antenna frequency of the location tracking system, e.g., atapproximately 1.5 GHz) that extends from the proximal end of the housing136 and is approximately parallel to the ground, surface or pavementwhen the locate receiver is being normally operated by a technician (soas to reduce signal modulation with subtle movements of the locatereceiver). As also shown in FIG. 5, incorporated at the distal end ofelongated housing 136 is the detection electronics 131, including RFantenna 127.

With respect to the actuation system 120, as shown in FIG. 5, theactuation system 120 includes an actuator 142, which for example may bea mechanical mechanism provided at the handle 138 in the form of atrigger that is pulled by a finger or hand of an user/technician. Inresponse to the signal/stimulus provided by the actuator 142, asdiscussed above the actuation system may provide an actuation signal 121to the processor 118 to indicate an actuation. As discussed in furtherdetail below, pursuant to the execution by the processor 118 of thelocate data algorithm 137, the actuation signal 121 may be used to causethe logging of information that is provided by one or more components ofthe locate receiver 110 so as to generate an electronic record of thelocate operation.

With respect to the general functionality facilitated and/or implementedby execution of the locate data algorithm 137, in some embodiments, auser may commence a locate operation with the locate receiver byinputting various information to the locate receiver, and/or selectingvarious operating options, via the user interface. As a non-limitingexample, the user may select from various menu options (using the userinterface and display as a menu-driven GUI), and or manually enter viathe user interface, the type of target object/facility to be located,the address of the locate operation, the ground type (e.g., grass,pavement, etc.), whether or not a separate transmitter is being used,the mode of the locate receiver (e.g., Peak v. Null, and active v.passive), whether the locate receiver is being operated in landmark modeor not (described further below), or any other information of interestto a locate operation.

In one exemplary implementation, the user may first power on the locatereceiver and log on, for example by entering a user ID. The user maythen navigate through a menu on a touch screen of the user interface toselect the target object to be located, for example selecting from amonga list of options (e.g., including facility types such as gas, sewer,cable, and phone, etc.). Similarly, the user may then navigate through amenu to select the ground type in the area of the locate operation(e.g., selecting from a list of options including grass, pavement, dirt,etc.). The user may then similarly select or input the frequency of anyapplied signal provided by a transmitter (in those embodiments in whicha transmitter is used), for example using a keypad of the user interfaceor a menu-driven GUI. It should be provided that these examples of useractions are non-limiting, and furthermore that in some embodiments oneor more of the pieces of information listed may be detectedautomatically and not be input/selected by the user.

Once the target object/facility type and any other relevant or desiredinformation is input and/or selected by the technician, and the appliedsignal from the transmitter is coupled to the target object (in thoseembodiments in which the locate receiver is used with a locatetransmitter, i.e., in active modes of operation as opposed to passivemodes in which no transmitter may be used), the locate receiver may beused in a variety of manners by the technician for a locate operation,in which the technician generally positions (e.g., sweeps) the locatereceiver over an area in which they expect to detect an undergroundfacility. More specifically, the technician positions the locatereceiver such that the RF antenna 127 (which may include more than oneantenna, as described further below) may receive/detect a magnetic fieldemitted by the target object (see underground facility 28 in FIG. 2).

In some embodiments, the locate receiver 110 is capable of operating ina null mode (e.g., capable of detecting a null signal when positionedover an object (e.g., facility) emitting a magnetic field), such that RFantenna 127 may comprise a null detection antenna 127 c. Alternatively,the locate receiver 110 is capable of operating in a peak detection mode(e.g., capable of detecting a peak signal when over an object (e.g.,facility) emitting a magnetic field), and the RF antenna 127 comprisestwo peak detection antennae 127 a and 127 b, which may be positionedsubstantially parallel to each other but at different positions withinthe locate receiver (e.g., at different heights). In some embodiments,the locate receiver 110 is capable of operating in both peak detectionand null detection modes, and the RF antenna 127 may comprise threeantennae, e.g., one null detection antenna 127 c and two peak detectionantennae 127 a and 127 b, as shown in FIG. 5. However, RF antenna 127may comprise any other number, type, and orientation of antennae, as thelocate receivers described herein are not limited in these respects.

With reference again to FIG. 4, the RF antenna 127 may be coupled to thedetection circuit 139 such that the signal(s) received/detected by theRF antenna 127 may be provided to the detection circuit 139 as an outputsignal of the RF antenna. The output signal of the RF antenna may be anyfrequency detectable by the antenna, and in some embodiments may bebetween approximately 512 Hz and 1 MHz, although these non-limitingfrequencies are provided primarily for purposes of illustration. Asmentioned, the output signal of the RF antenna 127, which in someembodiments is an analog signal, may be provided to detection circuit139, which may perform various functions. For example, the detectioncircuit 139 may perform various “front-end” operations on the outputsignal of RF antenna 127, such as filtering, buffering, frequencyshifting or modulation, and/or pre-amplifying the output signal.Furthermore, the detection circuit 139 may perform additional functions,such as amplifying and/or digitizing the output signal provided by RFantenna 127. It should be appreciated, however, that the types offunctions described as being performed by detection circuit 139 arenon-limiting examples, and that other functions may additionally oralternatively be performed.

After detection circuit 139 has operated on the signal from RF antenna127 (e.g., by filtering, buffering, amplifying, and/or digitizing, amongother possible operations), it may provide a signal to processingcircuit 133. The processing circuit 133 may process the signal(s)provided by detection circuit 139 in any suitable manner to determineany information of interest. For example, according to one embodiment,the processing circuit 133 may process the signal(s) from detectioncircuit 139 to determine a magnetic field strength of a magnetic fielddetected by RF antenna 127. The processing circuit 133 may process thesignal(s) from detection circuit 139 to determine an amplitude and/ordirection of the electrical current creating the magnetic field(s)detected by RF antenna 127. Processing circuit 133 may performoperations to calculate, for example, the depth and location of thetarget facility based on the electromagnetic fields detected by RFantenna 127. Processing circuit 133 may be an analog circuit or adigital microprocessor, or any other suitable processing component forperforming one or more of the operations described above, or any otheroperations of interest with respect to signals detected by RF antenna127. Also, it should be appreciated that processing circuit 133 andprocessor 118 may be a single processor in some embodiments, as theillustration of them as distinct in FIG. 4 is only one non-limitingexample.

According to various embodiments, the manner in which locate informationderived from one or more exemplary input devices is logged to localmemory 122 (e.g., pursuant to the locate data algorithm 137) may dependat least in part on the type of data being logged, as the operation oflocate receiver 110 is not limited in this respect. Some generalconcepts relating to data acquisition are introduced initially below anddiscussed in greater detail in connection with FIG. 6.

In some exemplary implementations, various types of locate information,including data from timing system 128 and/or location tracking system130, may be automatically logged continuously (e.g., in the form ofstreaming packets with flag fields, as described below, or in any othercontinuous form) or periodically to the local memory 122, may be loggedin response to one or more types of conditions/events (e.g., may belogged automatically when a particular condition/event occurs), and/ormay be logged at any suitable times. In particular, in oneimplementation, logging may occur at periodic intervals duringperformance of a locate operation, such as every second, every fiveseconds, every minute, or at any other suitable time interval.

According to another embodiment, various locate information, includingtiming information and/or geographic information from timing system 128and location tracking system 130, respectively, may be logged inresponse to particular types of events, such as detecting an undergroundfacility or detecting the absence of an underground facility. Suchevents may be identified by signals output by processing circuit 133 toprocessor 118. As a non-limiting example, timing information and/orgeographic information may be logged when a characteristic (e.g.,magnetic field strength) of a signal detected by RF antenna 127 isgreater than a particular threshold value, which may be indicated by asignal output from processing circuit 133 to processor 118, and whichoccurrence may be indicative of the presence of an underground facility.Similarly, in some embodiments, timing information and/or geographicinformation may be logged when a signal detected by RF antenna 127 has amagnitude above a first threshold and the gain of the locate receiver110 is above a second threshold. It should be appreciated that variouscombinations of detected signals detected by locate receiver 110 may beused to trigger logging of information (e.g., timing information and/orgeographic information) to local memory. It should also be appreciatedthat any information available from the location tracking system 130(e.g., any information available in various NMEA data messages, such ascoordinated universal time, date, latitude, north/south indicator,longitude, east/west indicator, number and identification of satellitesused in the position solution, number and identification of GPSsatellites in view and their elevation, azimuth and SNR values, dilutionof precision values) may be included in geographic informationconstituting all or a portion of logged locate information.

In some embodiments, various locate information may be logged inresponse to detection of a pattern of events, or deviation from apattern of events. For example, a pattern of magnetic field strengthmagnitudes (e.g., a relatively constant magnetic field strength for agiven time, an increasing magnetic field strength, a decreasing magneticfield strength, etc.) may be detected by the locate receiver, which maytrigger logging of timing information and/or geographic information.Deviation from a pattern, such as a historical pattern or expectedpattern may also trigger logging of information. For example, a user'shistorical use patterns of a locate receiver may be compared toinformation collected about the use of the locate receiver during agiven job, and if a deviation is detected then logging of timing and/orgeographic information may be triggered. The patterns or deviations frompatterns may relate to patterns in magnetic field strength, magneticfield frequency, signal gain, user operation, any other informationdescribed herein, or any combination of such information.

In some embodiments, alternatively or in addition to “automatic” loggingof locate information based on some condition or event, a user of thelocate receiver 110 may “manually” trigger logging of timinginformation, geographic information, and/or any other data associatedwith a locate operation or locate receiver (locate information), forexample by manipulating a control (e.g., button, knob, joystick) of theuser interface 126 or, as discussed above, by actuating an actuator 142integrated or otherwise associated with the locate receiver (as shown inFIG. 5), which may be part of the actuation system 120 and which maycause a signal 121 to be sent to the processor 118 to initiate loggingof locate information. For example, according to some embodiments a usermay initiate the locate receiver 110 taking a depth measurement bydepressing a pushbutton of the user interface 126, or pulling/squeezingthe actuator 142, which may also trigger the logging of timinginformation and/or geographic information from timing system 128 andlocation tracking system 130. The depth measurement data, time data,and/or location data may then be logged in an electronic record 135 inlocal memory 122.

It should be appreciated that while the foregoing discussion focuses onlogging locate information to local memory 122, the locate informationmay also, or alternatively, be transmitted to remote computer 150 viacommunication interface 124. As with logging locate information to localmemory 122, the transmission of locate information to remote computer150 may be performed continuously, periodically in response to one ormore types of events, in response to user input or actuation of anactuator, or in any other suitable manner.

In yet other embodiments, the locate receiver 110 may be configured(e.g., via particular instructions executing on the processor 118) tooperate in multiple different modes to collect various informationrelating not only to a locate operation (locate information), butadditionally or alternatively various information relating to the worksite/dig areas in which the locate operation is performed. For example,in one implementation, the locate receiver may be configured to operatein a first “locate mode” which essentially follows various aspects ofthe operation of the locate receiver 110 described herein, and also maybe configured to operate in a second “landmark identification mode.”When switched into the landmark mode, the locate receiver may stopdetecting a magnetic field, e.g., the RF antenna of the locate receivermay be temporarily disabled in some embodiments. In other embodiments,the locate receiver may continue to operate and the landmark mode mayrepresent additional functionality added to the locate receiverfunctionality. Additional details of the landmark mode are discussedfurther below.

III. Format, Content and Process of Generating Electronic Records ofLocate Information

As noted above, locate information may be generated, logged and/ortransmitted by a locate device according to a variety of manual,semi-automatic, and/or automatic techniques; for example, in someimplementations, a technician may actuate an actuator (e.g., pull atrigger, push a button) in response to which certain locate informationmay be generated, acquired, logged and/or transmitted. In otherimplementations, one or more predetermined conditions may be established(e.g., one or more thresholds, patterns, etc.) that, when present, maycause generation, acquisition, logging and/or transmission of locateinformation.

In exemplary methods for generating an electronic record of locateoperations according to some embodiments of the invention pursuant tomanual actuation of an actuator (or manipulation of a user interfacecontrol mechanism), as discussed in greater detail below, for a givenactuation the processor 118 may generate an “actuation data set,” e.g.,a set of data that is somehow organized, formatted, and/or indexed tocorrespond to a given actuation of the locate receiver. For example, fora given actuation data set, the processor 118 may request the locationtracking system 130 to provide geographic information at one or moretimes during the actuation (e.g., periodically at regular intervals).Thus, an actuation data set of an electronic record for a givenactuation of the locate receiver may have multiple pieces of geographicinformation (and associated time stamps) representing the location ofthe locate receiver at multiple times during a corresponding actuation.Additionally, for a given actuation, the processor 118 also may requestthe processing circuit 133 to provide various locate signal information(e.g., relating to one or more characteristics of the detected magneticfield) as part of the actuation data set. The processor also may includein the actuation data set ticket information and service-relatedinformation, which may be collected (e.g., via one or more of the userinterface 126 and the communication interface 124) before acorresponding actuation, stored in memory 122 and retrieved from thememory for entry into the electronic record upon or during thecorresponding actuation, or collected and entered into the electronicrecord upon or during the corresponding actuation.

While the collection and logging of locate information to generate anelectronic record is discussed in some aspects, for purposes ofillustration, in terms of actuation data sets (i.e., a set of data thatis associated and logged with a corresponding actuation of the locatereceiver), it should be appreciated that various embodiments of thepresent invention are not limited in this respect. More generally, anelectronic record of a locate operation may be generated in any of avariety of manners, have a variety of file formats and/or datastructures, and include any of a variety of locate information.

FIG. 6 is a flow diagram of an exemplary process 600 for collectinglocate information during operation of a locate receiver 110 andgenerating an electronic record, according to one embodiment of thepresent invention. It should be appreciated that as various locateinformation is collected and logged in the process 600, such locateinformation also may be transmitted from the locate receiver (e.g., toremote computer 150) to facilitate essentially real-time monitoring ofthe locate operation, and/or remote generation of an electronic recordof the locate operation.

In block 602 of the process 600 shown in FIG. 6, ticket informationand/or service-related information may be received (e.g., via one ormore of the user interface 126 and the communication interface 124 oflocate receiver 110) and this information optionally may be stored inwhole or in part in local memory 122 of the locate receiver. The ticketinformation and/or service-related information may be receivedelectronically in any of a variety of formats, and the processor may beconfigured to appropriately parse the information for subsequent entryinto an electronic record.

For example, in some embodiments, the ticket information may be receivedas part of an electronic locate request ticket, and individualrespective pieces of ticket information (e.g., ticket number, work siteaddress information, requesting party, etc.) may be extracted or derivedfrom the electronic locate request ticket. In other embodiments, variousaspects of ticket information may be input by a user/technician via theuser interface.

For example, in block 602 the process 600 may provide for the entry ofany of a variety of text information for inclusion in an electronicrecord and/or selection by a user/technician (e.g., via the userinterface) of various information to be included in an electronic recordas part of ticket information (and/or service-related information). Oneexample of such information may relate to a ground type in and aroundthe work site/dig area at which the locate operation is taking place. Insome implementations, a text description of the ground type may beentered and stored as part of the electronic record. In anotherexemplary implementation, the processor 118 controls the user interface126 (including display 146) so as to display information to thetechnician to facilitate such a selection. In particular, a ground typeselection submenu may be displayed, including one or more categories ofground types displayed in any of a variety of manners (e.g., as a listof text entries, an arrangement of icons symbolizing respectivecategories, labeled symbols, etc.). Examples of ground type categoriesthat may be displayed in such a submenu include, but are not limitedto: 1) “Pavement;” 2) “Grass;” 3) “Rough/Rocky;” 4) “Dirt;” 5)“Gravel/Sand;” and 6) “Other.” More generally, any number and variety ofground type categories may be presented to the technician via the userinterface in alphabetically ordered lists, numerically ordered lists, orother types of ordered text-based or symbolic arrangements, for example.In yet another exemplary implementation, the user interface may includea microphone and the processor may be configured to accept and processaudible commands, such that a ground type category may be accomplishedvia voice-activated commands by simply speaking into the microphone.

Similarly, with respect to service-related information, auser/technician may manually enter some aspects of this information viathe user interface/display, while other aspects may already be availablein other memory locations (e.g., the locate receiver ID or serialnumber, a technician ID to which the locate receiver is assigned orchecked-out, etc.) and/or may be received electronically.

While block 602 is illustrated as one element of the process 600, itshould be appreciated that respective pieces of information received asinput in block 602 may be received at different times and via differentinterfaces/sources, and thus may occur at different points in theprocess 600. It should also be appreciated that block 602 is an optionalstep in the process 600, and that more generally a process forcollecting locate information to generate an electronic record need notnecessarily include collection of one or both of ticket information andservice-related information.

In block 604, the locate technician utilizes the user interface 126 toindicate the initiation of a locate operation. For example, thetechnician may press a button, operate a joy-stick, or touch a touchscreen display portion of a graphical user interface to commence alocate operation. In response, a “job initiation signal” is provided tothe processor 118 (e.g., via a switch closure and a ground or DC levelapplied to an I/O pin of the processor, or by the user interfaceproviding a signal to the processor) to initiate generation of anelectronic record. Alternatively, a remote job initiation signal may bereceived by the processor via the communication interface from anotherdevice, such as the remote computer 150.

In response to the job initiation signal, in block 606 the processoropens a file in the memory 122 in which to store the electronic record135, and assigns a file identifier to the opened file. In one example,the file identifier assigned to the opened file may be or include one ormore of a job number (“job ID”) or ticket number derived from the ticketinformation and/or the service-related information, an identifier forthe locate receiver itself, and an identifier for a remote computerassociated with the locate receiver (e.g., for either remote controloperation of the device and/or data uploading/downloading). To this end,if ticket information and/or service-related information is notpreviously available (e.g., if no information is received in block 602),the technician optionally may be prompted to manually enter (e.g., via a“wizard” or sequence of dialogues germane to obtaining relevantinformation displayed on the display of the user interface) variouselements of ticket information and/or service-related information fromwhich a file identifier may be derived, or provide other informationthat may be used as a file identifier.

A file opened in block 606 for purposes of storing an electronic recordmay have any of a variety of formats and include any of a variety ofdata structures. In one embodiment, the processor initially opens up a“flat file” for collection and logging of locate information tofacilitate generation of an electronic record. As known in the art, aflat file is a plain text or mixed text/binary file containing one entry(data record) per line, in which each entry may have multiple fieldscontaining respective values, and wherein the respective values may beseparated by delimiters (e.g., commas) or have a fixed length. In oneexemplary implementation, the processor 118 logs data into a flat fileopened for the electronic record as a succession of time stamped “evententries.” Some event entries may be related specifically to actuationand/or logged in response to actuation of the locate receiver (e.g., theprocessor 118 receiving an actuation signal 121), while other evententries may be related to automatic logging of data as discussed above(e.g., upon meeting or exceeding a threshold condition, meeting ordeviating from a pattern, etc.). Other event entries may be moregenerally related in some manner to overall operation of the locatereceiver or the locate operation itself, but not necessarily associatedwith one or more particular actuations (e.g., start/pause/stop locateoperation, power/battery status, communication link/network connectionstatus, etc.), and these other event entries may be logged at virtuallyany time (in some cases irrespective of one or more actuations).

Accordingly, it should be appreciated that in one aspect of thisembodiment a flat file for an electronic record may contain a successionof time stamped event entries on respective lines, in which one or moreevent entries may have multiple delimited fields/values, and wherein atleast some of the event entries may relate to actuation of the locatereceiver and/or automatic logging of data. In another aspect, one ormore fields/values in a given event entry may specifically indicate insome manner whether or not the event is associated with an actuation ofthe locate receiver. In general, an “actuation event entry” constitutesan entry in a file for an electronic record that is in some mannerspecifically related to, and/or logged in response to or during,actuation of the locate receiver, and multiple actuation event entriesfor a given actuation constitute an actuation data set for thatactuation. Again, it should be appreciated that a file for an electronicrecord may include one or more other event entries that may not beparticularly associated with an actuation.

In other embodiments, the file for an electronic record may or may notbe a flat file, and event entries associated with actuations (actuationevent entries) may be somehow identified and differentiated from otherevent entries that are not associated with an actuation. For example, afile for an electronic record may include a particular data structure orformat that segregates or separates in some manner event entriesassociated with successive actuations from those event entries that arenot particularly associated with actuations (and/or may be common tomultiple actuations or a group of actuations). In yet other embodiments,as discussed below, locate information may be initially collected andlogged in a first file for an electronic record in a first format (e.g.,a flat file including a succession of time-stamped event entries as “rawdata” for the locate operation) that may be stored and/or transmittedfor any of a variety of purposes, and then reformatted and/orreorganized in some manner in one or more subsequent files (e.g., a filehaving a particular data structure that segregates/separatesactuation-related information from other information in differentfields/elements of a data structure) for archiving and/or transmissionto one or more other devices/processors.

Once a file for an electronic record is opened in block 606, in block608 the processor can begin collecting and logging various locateinformation, i.e., logging in the electronic record (and/or transmittingvia the communication interface) actuation event entries and/or otherevent entries. In one exemplary implementation, the processor may beprogrammed so as to poll one or more input devices and/or othercomponents of the locate receiver to receive information, either once ormultiple times/periodically following the job initiation signal, and logresponses to these polls (“polling events”) as event entries withassociated time stamps. Examples of entries corresponding to pollingevents that may be logged into the file for the electronic record(and/or transmitted) include, but are not limited to, one or more “powerstatus event entries” including power information associated with thepower source 114, one or more “ticket information event entries”including ticket information (e.g., as received from the user interfaceor the communication interface, retrieved from local memory, etc.), oneor more “service-related information event entries” including theservice-related information (e.g., as received from the user interfaceor the communication interface, retrieved from local memory, etc.), andone or more “communication interface event entries” including statusinformation regarding operation of the communication interface (e.g.,network communication available/unavailable).

Additionally or alternatively, the processor may be programmed so as torespond to one or more signals designated as “interrupt events” from oneor more components of the locate receiver. Such interrupt events causelogging of information in the electronic record (and/or transmission ofinformation) upon/following the processor detecting the correspondingsignal(s). For example, the “job initiation signal” itself mayconstitute an interrupt event, in response to which the processor 118not only opens a file for the electronic record but, once the file isopened, the processor may request timing information from the timingsystem 128 and log into the electronic record a “start job event entry”including a job initiation time stamp associated with receipt of the jobinitiation signal.

In a similar manner, following commencement of a locate operation, thelocate technician may utilize the user interface 126 (e.g., press abutton, operate a joy-stick, or touch a touch screen display portion ofa graphical user interface) to pause, restart, and/or indicatecompletion of the locate operation, and these actions may constituteinterrupt events. For example, as indicated in block 610 of FIG. 6, a“pause signal” may be provided by the user interface to the processor,in response to which the processor may request timing information fromthe timing system and log a “pause job event entry” including a pausejob time stamp associated with the at least one pause signal. When thetechnician is ready to continue, as shown in block 612 of FIG. 6 thetechnician may indicate this via the user interface and a “restart jobevent entry” similarly may be logged. When the locate operation isdeemed by the technician to be completed, as noted in block 614 of FIG.6 the technician may utilize the user interface so as to provide a “stopsignal” to the processor, in response to which the processor may requesttiming information from the timing system and log a “stop job evententry” including a stop job time stamp associated with the stop signal.

Additionally, the locate technician may utilize the user interface 126to denote the beginning and end of a locate operation for a particularfacility type, and these actions may constitute interrupt events. Forexample, upon beginning a locate operation for a given facility type,the technician may select “line start” from the user interface, and acorresponding “line start signal” may be provided by the user interfaceto the processor, in response to which the processor may request timinginformation from the timing system and log a “line start event entry.”Similarly, when the technician wishes to indicate completion of thelocate operation for a given facility type, the technician may select“line stop” from the user interface, and a corresponding “line stopsignal” may be provided by the user interface to the processor, inresponse to which the processor may request timing information from thetiming system and log a “line stop even entry.”

While various events are noted above as examples of “polling events” asopposed to “interrupt events,” it should be appreciated that theinventive concepts discussed herein are not limited in these respects,and that the locate data algorithm 137 executed by the processor 118 maybe configured in any of a variety manners to designate various functionsperformed by and/or information provided by various components of thelocate receiver as polling events or interrupt events. For example, thepower source 114 may be configured to provide a “low battery signal” tothe processor, which when present is treated by the processor as aninterrupt event that may be logged by the processor and/or that maycause the processor to take some particular action (e.g., provide anaudible/visible alert; disable logging of further data, etc.). In oneaspect, absent the “low battery signal,” the processor may requeststatus information from the power source once or occasionally as apolling event. Similarly, the communication interface 124 may beconfigured to provide a “no network connection available signal” to theprocessor, which when present is treated by the processor as aninterrupt event (that is logged and/or causes the processor to take someaction), and when not present, the processor may poll the communicationinterface to request status information as a polling event.

Another example of an interrupt event is the automatic logging of locateinformation, for example one or more of timing information, geographicinformation, and locate signal information derived from the detectionelectronics 131. In particular, as discussed above, automatic loggingmay occur at periodic intervals during performance of a locateoperation, such as every second, every five seconds, every minute, or atany other suitable time interval. Alternatively, timing information,geographic information and/or locate signal information may be loggedwhen a characteristic (e.g., magnetic field strength) of a signaldetected by RF antenna 127 is greater than a particular threshold value,which may be indicated by a signal output from processing circuit 133 toprocessor 118, and which occurrence may be indicative of the presence ofan underground facility. Similarly, in some embodiments, timinginformation, geographic information and/or locate signal information maybe logged when a signal detected by RF antenna 127 has a magnitude abovea first threshold and the gain of the locate receiver 110 is above asecond threshold. Additionally, as noted above, various locateinformation may be logged in response to detection of a pattern ofconditions/events, or deviation from a pattern of conditions/events(e.g., a pattern of magnetic field strength magnitudes may be detectedby the detection electronics 131, which may cause automatic logging oftiming information, geographic information, and/or locate signalinformation).

Yet another example of an interrupt event is given by the actuationsignal 121 provided by the actuation system 120 upon actuation of theactuator 142 (i.e., a signal change-of-state indicating a transitionfrom a non-actuated state to an actuated state), in response to whichthe processor logs one or more actuation event entries in the electronicrecord. More specifically, in one implementation, the receipt of anon-actuated to actuated transition state of the actuation signal 121 bythe processor may cause an initial actuation event entry to be logged asa “start actuation event entry” having an associated time stamp (i.e., astart time for the corresponding actuation) and also cause the processorto subsequently poll one or more input devices for information duringthe corresponding actuation and until release of the actuator (i.e.,subsequent change of state of the actuation signal 121). In this manner,an actuation data set for a given actuation may include multipleactuation event entries.

For example, during actuation of the actuator, the processor may pollthe location tracking system 130 so as to receive geographicinformation, and in turn log one or more “geo-location data evententries” in the actuation data set for the corresponding actuation. Asdiscussed above in connection with FIGS. 4 and 5, in one exemplaryimplementation the location tracking system is configured to providegeographic information at an information update rate of approximately 5Hz, and the processor may log respective updates of geographicinformation provided by the location tracking system at this update rateduring an actuation as multiple geo-location data event entries of theactuation data set. It should be appreciated, however, that methods andapparatus according to various embodiments of the present invention arenot limited in this respect, and that other geographic informationupdate rates may be employed in various implementations (e.g., updaterates of up to approximately 100 Hz), based in part on the particularlocation tracking system employed. Furthermore, it should be appreciatedthat in some implementations the geographic information provided by thelocation tracking system 130 may include one or more longitudecoordinates, latitude coordinates, and a corresponding geo-location datatime stamp at which a given set of longitude/latitude coordinates areobtained by the location tracking system; accordingly, a givengeo-location data event entry in an actuation data set may include alongitude coordinate, a latitude coordinate, and the correspondinggeo-location data time stamp.

Similarly, in some implementations, pursuant to an interrupt provided bythe actuation signal 121, the processor may subsequently poll one ormore of the timing system 128 and the detection electronics 131 so as toreceive timing information and/or locate signal information during acorresponding actuation, and in turn log one or more of a “timing evententry,” and a “locate signal event entry” as part of the actuation dataset. Any of a variety of locate signal information as discussed abovemay be collected and logged during actuation in response to processorpolling of the detection electronics 131.

Additionally, in some implementations, pursuant to an interrupt providedby the actuation signal 121, the processor may subsequently poll one ormore of the user interface 126, the communication interface 124, and thelocal memory 122 to retrieve ticket information and/or service-relatedinformation for logging into an actuation data set. As discussed above,in some implementations the receipt/retrieval of ticket informationand/or service-related information may be treated as a polling event notnecessarily associated with actuations, and this information need not beincluded in one or more actuation data sets. However, in otherimplementations it may be desirable to include at least some aspect ofticket information and/or service related information in each actuationdata set, notwithstanding the possible redundancy of data content inrespective actuation data sets.

Another example of an interrupt event is given by a change-of-state ofthe actuation signal 121 indicating a transition from the actuated stateto the non-actuated state, i.e., release of the actuator 142. Inresponse to this event, the processor may request information from thetiming system 128 and log an “end actuation event entry” including anend time stamp.

In yet another embodiment, the processor 118, executing locate dataalgorithm 137, may be configured to repeatedly/regularly poll allavailable input devices and other components of the locate receiver(e.g., in a predetermined order, in response to receipt of the jobinitiation signal), as well as continually monitor for a variety ofpossible interrupt events, and generate an essentially continuous streamof data packets including locate information received pursuant to thesepolling and/or interrupt events. In one aspect of this embodiment, eachdata packet of locate information may include a header, one or more flagfields, and one or more information payload fields. For example, in oneimplementation, the header for each packet may include one or more of ajob ID (e.g., ticket identifier), technician ID, device ID (e.g., serialnumber), packet type ID, and/or a time stamp corresponding to logging ofinformation/generation of the packet. Each packet also may include oneor more payload fields for carrying information provided by the polleddevice(s) or devices generating interrupts, and one or more flag fieldsthat are set (or reset) upon occurrence of one or more predeterminedinterrupt events (e.g., pull/depress actuator, release actuator,automatic log due to some condition/event, low power, communication linkfail, etc.). In this manner, a continuous stream of data may be providedas an output by the processor, in which certain interrupt events, suchas an actuation and/or release of the actuator, or automatic logging ofdata, “tag” certain data packets via an interrupt flag. In yet otheraspects of this embodiment, all data packets thusly generated may bestored in the file opened for the electronic record and/or transmittedfrom the locate receiver in essentially real time; alternatively, onlycertain data packets with one or more predetermined flags set may bestored and/or transmitted.

Table 1 below illustrates an example of a portion of the contents of arelatively simple flat file for an electronic record that may begenerated by the process 600 of FIG. 6:

TABLE 1 TIME LAT LONG EVENT FACILITY TYPE 1:23:00.00 PM −80.3851 25.5604Detection ORANGE 1:23:00.20 PM −80.3851 25.5604 Detection ORANGE1:23:00.40 PM −80.3851 25.5604 Detection ORANGE 1:23:00.60 PM −80.385125.5604 Detection ORANGE 1:23.00.80 PM −80.3851 25.5604 Detection ORANGE1:23:01.00 PM −80.3851 25.5604 Detection ORANGE 1:23:01.20 PM −80.385125.5604 Detection ORANGE 1:23:01.40 PM −80.3851 25.56039 DetectionORANGE 1:23:01.60 PM −80.3851 25.56039 Detection ORANGE 1:23:01.80 PM−80.3851 25.5604 Detection ORANGE 1:23:02.00 PM −80.3851 25.5604Detection ORANGE

The portion of the file shown in Table 1 corresponds to multiple locatesignal event entries indicating detection of a facility (one entry perline). Each entry has a time stamp (e.g., entries are logged at a rateof approximately five events per second) and further includes multiplefields having respective values (e.g., as comma separated values) forlatitude and longitude coordinates received from the location trackingdevice, an event indicator indicating that the locate receiver isdetecting (“Detection”), and a color code indicating the type offacility detected (e.g., as established by the American Public WorksAssociation and shown further below in Table 7).

As noted above, it should be appreciated that the portion of the fileshown in Table 1 is provided primarily for purposes of illustration, andthat the format and/or content for respective event entries and the fileitself for an electronic record generated by and/or based on theinformation collection process discussed above in connection with FIG. 6may have any of a variety of different formats and/or content.

To this point, Tables 2 through 5 below provide examples of variousevents for which event entries may be logged in a file for an electronicrecord and/or transmitted by the locate receiver, exemplary formats forthese event entries, and exemplary file formats for files havingmultiple such entries, according to another embodiment of the presentinvention.

Job Started/Paused/Restarted/Completed Events: This event entry formatprovides information about when a locate operation (“job”) is startedand completed in addition to capturing details about if and when the jobwas paused and restarted.

TABLE 2 Format INFO+JOBS: (DATE) (TIME) (DEV_ID) (JOB_ID) (STATE)<CR><LF> Examples INFO+JOBS: DATE(2009-04-15) TIME(12:03:44) DEV(2334)JOB(4000) (STARTED) <CR> <LF> INFO+JOBS: DATE(2009-04-15) TIME(12:11:44)DEV(2334) JOB(4000) (PAUSED) <CR> <LF> INFO+JOBS: DATE(2009-04-15)TIME(12:51:44) DEV(2334) JOB(4000) (RESTARTED) <CR> <LF> INFO+JOBS:DATE(2009-04-15) TIME(13:09:44) DEV(2334) JOB(4000) (END) <CR> <LF>

Actuation Events: As has been described, according to at least oneembodiment of the present invention, a locate receiver may be operatedto collect and/or transmit locate information upon actuation by a user.Table 3 illustrates an example of an entry relating to the actuationevent. Locate information from one or more input devices/othercomponents of the locate device may be recorded upon actuation toprovide information about the job in progress. The facility typeinformation may be entered/selected by a user as described previously,and may be recorded in the event, for example, according to thecolor-coding scheme of Table 7 discussed further below.

TABLE 3 Format INFO+ LCTR: (DATE) (TIME) (GPS data) (FACILITY TYPE)(GROUND TYPE) (MAGNETIC FIELD STRENGTH AS % OF FULL SCALE info)(DETECTED SIGNAL FREQUENCY) (GAIN) <CR><LF> Examples INFO+LCTR:DATE(2009-04-15) TIME(12:04:44)GPS($GPGGA,120443,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )FACILITY TYPE (YELLOW) GROUND TYPE (PAVEMENT) STRENGTH(80)FREQUENCY(512) GAIN (10) <CR><LF> INFO+LCTR: DATE(2009-04-15)TIME(12:04:45)GPS($GPGGA,120445,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )FACILITY TYPE (YELLOW) GROUND TYPE (GRASS) STRENGTH(81) FREQUENCY (512)GAIN (10) <CR><LF> INFO+LCTR: DATE(2009-04-15) TIME(12:04:46)GPS($GPGGA,120446,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )FACILITY TYPE (YELLOW) GROUND TYPE (DIRT) STRENGTH(80) FREQUENCY(512)GAIN (11) <CR><LF>

Locate Device Status Events: The status event of a locate devicecollects various locate-related information and/or information onoperating characteristics of the locate device on a periodic basis whilea job is in progress (e.g., pursuant to processor polls). An example isshown below in Table 4. In the non-limiting example, the entries includeinformation about the mode of the locate receiver (e.g., peak v. null).It should be appreciated, however, that other information mayadditionally or alternatively be included in the event entry.

TABLE 4 Format INFO+LCTSTAT: (DATE) (TIME) (GPS data) (MODE status)(MEMORY used in %) (BATTERY level) <CR><LF> Examples INFO+LCTSTAT:DATE(2009-04-15) TIME(12:04:00)GPS($GPGGA,120400,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )MODE(PEAK) MEM(65) BAT(3)<CR><LF>

Error Events: Should any input device or other component of the locatedevice encounter a significant error condition, this may be logged as anevent. In some cases, the user/technician also may be notified of theerror through the user interface 126 (visible alert on display, audiblealarm/alert, etc.). Similar event formats may be adopted for warningalerts/events and informational alerts/events.

TABLE 5 Format INFO+ERR: (DATE) (TIME) (GPS data) (MEMORY used in %)(BATTERY level) <CR><LF> Examples INFO+ERR: DATE(2009-04-15)TIME(12:04:00)GPS($GPGGA,120400,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )MEM(65) BAT(3)<CR><LF>

It should be appreciated that the event types described above and thelogged location information shown in the corresponding tables areprovided primarily for purposes of illustration, and are not limiting.Thus, events of various other types and with various other informationmay be logged into an electronic record.

With respect to file formats for electronic records including the evententries outlined above in Tables 2 through 5, two exemplary fileformats, namely ASCII and XML, are provided below for purposes ofillustration. In various implementations, a given locate receiver may beparticularly configured to store and/or transmit electronic records andrespective entries therein in either format (or other formats). Withrespect to identification of files/electronic records, a standard namingscheme/format may be adopted, for example, including an identifier forthe remote computer with which the locate receiver may be communicating(“ServerID”), an identifier for the locate receiver itself (“LocRecID”),and an identifier for the locate operation/job (“JobID”), and having theformat “ServerID_(—LocRecID) _(—Job ID.”)

ASCII Data Format: This format allows low-level remote processingengines to quickly and easily receive, parse, and react to locateinformation logged and/or transmitted by the locate receiver. An exampleof an electronic record formatted in ASCII based on the event entriesoutlined in Tables 2 through 5 is as follows:

INFO+JOBS: DATE(2009-04-15) TIME(12:03:44) DEV(2334) JOB(4000) (STARTED)<CR> <LF> INFO+LCTSTAT: DATE(2009-04-15) TIME(12:04:00)GPS($GPGGA,120400,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )MODE(PEAK) MEM(65) BAT(3)<CR><LF> INFO+LCTR: DATE(2009-04-15)TIME(12:04:44)GPS($GPGGA,120443,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9, M,,*47 )FACILITY TYPE (YELLOW) GROUND TYPE (PAVEMENT) STRENGTH(80)FREQUENCY(512) GAIN (10) <CR><LF> INFO+LCTR: DATE(2009-04-15)TIME(12:04:45)GPS($GPGGA,120445,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )FACILITY TYPE (YELLOW) GROUND TYPE (GRASS) STRENGTH(81) FREQUENCY (512)GAIN (10) <CR><LF> INFO+LCTR: DATE(2009-04-15) TIME(12:04:46)GPS($GPGGA.120446,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )FACILITY TYPE (YELLOW) GROUND TYPE (DIRT) STRENGTH(80) FREQUENCY(512)GAIN (11) <CR><LF> INFO+LCTSTAT: DATE(2009-04-15) TIME(12:05:00)GPS($GPGGA,120500,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47 )MODE(PEAK) MEM(65) BAT(3)<CR><LF> INFO+JOBS: DATE(2009-04-15)TIME(12:10:03) DEV(2334) JOB(4000) (PAUSED)<CR> <LF> INFO+JOBS:DATE(2009-04-15) TIME(13:01:43) DEV(2334) JOB(4000) (RESTARTED)<CR> <LF>INFO+JOBS: DATE(2009-04-15) TIME(13:20:30) DEV(2334) JOB(4000) (END)<CR><LF>

XML Data Format: This format allows transmission of self-describing dataelements from the locate receiver, in some instances reducing processingerrors and reducing the risks and effort involved in upgrades and datachanges. An example of an electronic record formatted in XML based onthe event entries outlined in Tables 2 through 5 is as follows:

<DEV ID=2334> <JOB ID=4000> <ACTIVITY> <DATE>2009-04-15</DATE><TIME>12:03:44</TIME> <STATUS>Started</STATUS>  </ACTIVITY>  <ACTIVITY> <DATE>2009-04-15</DATE>  <TIME>12:04:00</TIME>  <GPS>($GPGGA,120400,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47</GPS> <FACILITY TYPE> <COLOR>Yellow</COLOR> <VALID>True</VALID>  </FACILITY><SWITCH>Pressed</SWITCH> </ACTIVITY> </JOB> </DEV> 

Table 6, shown below, lists another example of the contents of anelectronic record of locate information that may be generated and storedand/or transmitted relating to operation of a locate receiver, accordingto one non-limiting embodiment. The electronic record shown in Table 6includes a record number (record #1001), an identification of theservice provider, an identification of the user (i.e., the locatetechnician operating the locate receiver), and an identification of thelocate receiver. The mode of operation of the locate receiver (e.g.,peak, and in some scenarios an indication of active or passiveoperation) may also be included. Timing information (timestamp data)from a timing system of the locate receiver and geographic informationfrom a location tracking system of the locate receiver may also beincluded. The signal strength and signal frequency entries of theelectronic record indicate characteristics of a signal (e.g., a magneticfield) detected by the locate receiver, for example emitted from anunderground facility. The signal strength is listed in the example ofTable 6 as a percentage of the maximum detectable by the locatereceiver, although it should be appreciated that other units ofmeasurement may alternatively be used. The gain entry indicates the gainsetting of the locate receiver. The electronic record also includes anentry for the depth of the facility targeted, as may be determined bytaking a depth measurement using a locate receiver (e.g., by calculatinga difference in magnetic field strength detected by two differentantennae at two different locations within a locate receiver), and forthe facility type (e.g., gas, electric, etc.) and ground type in thearea of the locate operation. The electronic record of Table 6 alsoincludes the address of the locate operation and the party requestingthe locate operation. Lastly, Table 6 includes information about theremaining battery life of the locate receiver for those embodiments thatinclude a battery.

TABLE 6 Example Electronic Record For Locate Receiver Record Serviceprovider ID 0482 # 1001 User ID 4815 Receiver ID 7362 Receiver modeMode=Peak Receiver mode PASSIVE Timestamp data 12-Jul-2008; 09:35:15Geo-location data 2650.9348,N,08003.5057,W Signal strength (% of 85%maximum) Gain 45 Signal frequency 1 kHz Facility depth 3.4 metersFacility type Gas (yellow) Ground type Pavement Battery strength data85% Locate request data Requestor=XYZ Construction Company, Requestedservice address=222 Main St, Orlando, FL

It should be appreciated that Table 6 represents only one non-limitingexample of an electronic record of locate information which may begenerated in accordance with the operation of a locate receiver,according to one embodiment. In particular, a single electronic recordof locate information collected in connection with operation of a locatereceiver may include multiple entries of a given data type. For example,while Table 6 illustrates an electronic record including a single GPSdata point, it should be appreciated that multiple GPS data points maybe taken and stored within a single electronic record. The multiple GPSdata points may be taken in response to a single actuation event (e.g.,single actuator pull by a technician), in response to multiple actuationevents (e.g., multiple actuator pulls by a technician), or in othermanners. Thus, multiple pieces of data may be collected for anelectronic record of a locate operation, and it should be appreciatedthat any single electronic record may include multiple entries.

With regard to color information that may be included in any of theevent entries and electronic records discussed herein, Table 7 belowshows an example of a color code used to identify facilities to bedetected during a locate operation.

TABLE 7 Correlation of color to facility type Color Code Facility TypeRed Electric power lines, cables or conduits, and lighting cables YellowGas, oil, steam, petroleum, or other hazardous liquid or gaseousmaterials Orange Communications, cable television, alarm or signallines, cables, or conduits Blue Water, irrigation, and slurry linesGreen Sewers, storm sewer facilities, or other drain lines WhiteProposed excavation Pink Temporary survey markings Purple Reclaimedwater, irrigation, and slurry lines Black Mark-out for errant lines

FIG. 7 illustrates an exemplary data structure for an electronic record135, according to another embodiment of the present invention, that maybe generated by and/or based on information collected during the process600 discussed above in connection with FIG. 6. In the exemplary datastructure of FIG. 7, information is arranged in terms of actuation datasets, to illustrate the storage of data pursuant to actuations of alocate receiver. It should be appreciated however, that data structuressimilar to that shown in FIG. 7 may be generated and/or based, at leastin part, on automatic logging of various locate information, asdiscussed above.

As shown in FIG. 7, the record 135 includes a file identifier 701 (e.g.,one or more of Job ID, LocRecID, ServerID, etc.) and a plurality ofactuation data sets 1 through N (with reference numbers 702A, 702B, 702C. . . 702N), wherein each actuation data set is associated with acorresponding actuation of a locate receiver. For purposes of thefollowing discussion, FIG. 7 shows additional details of the datastructure for actuation data set 3 702C, showing several fields in whichdata (e.g., actuation event entries) may be entered to constitute theactuation data set. While only the exemplary details of the datastructure of actuation data set 3 are shown in the electronic record 135of FIG. 7, it should be appreciated that multiple actuation data sets ofthe electronic record 135 may have the same data structure as that shownfor actuation data set 3 in FIG. 7.

The data structure of the actuation data set 3 702C of the electronicrecord 135 shown in FIG. 7 includes a start location field 704(corresponding to geo-location data shown in Table 2 when an actuator ispressed), an end location field 713 (corresponding to geo-location datashown in Table 2 when an actuator is released), a start time field 706(corresponding to timestamp data shown in Table 2 when an actuator ispressed), an end time field 708 (corresponding to timestamp data shownin Table 2 when an actuator is released) and a duration field 709(corresponding to the duration of the actuator being held).Additionally, the data structure for entry 3 702C includes one or morefields 712A, 712B, . . . 712N for intermediate location data (e.g.,corresponding to 1^(st) interval location data, 2^(nd) interval locationdata . . . Nth interval location data which may be acquired while theactuator is being held). The actuation data set also may include alocate signal information field 710 including various data relating toone or more signals (e.g., corresponding to signal strength, gain,frequency, as shown in Table 6). Finally, the data structure for theentry 3 702C may include one or more ticket information fields 714(e.g., corresponding to Locate request data in Table 6) and one or moreservice-related information fields 716 (e.g., corresponding to Serviceprovider ID, User ID, and Receiver ID in Table 6).

In addition to one or more actuation data sets corresponding toactuations of a locate receiver, the electronic record 135 shown in FIG.7 may include one or more additional elements. For example, FIG. 7 showsan additional element 718 of the electronic record to store the totalnumber of entries in the record. Furthermore, according to anotherembodiment, various other information that may be common to multiple (orall) actuation data sets of a given electronic record may be stored inone or more additional elements of the electronic record that are notcontained within one or more of the actuation data sets themselves. Forexample, in one alternative implementation, one or more of the ticketinformation field 714, the service-related information field 716, andthe locate signal information field 710, which are shown as part of thedata structure for a given actuation data set of the electronic record,may instead be elements of the electronic record that are not includedwithin any one actuation data set (e.g., the information contained inone or more of the ticket information field, the service-relatedinformation field, and the locate signal information field 710 may becommon to all actuation data sets of a given electronic record).

IV. Landmark Identification Mode

In yet another embodiment of the present invention, a locate device suchas the locate receiver 110 shown in FIGS. 4 and 5 (as well as a locatetransmitter) may be configured (e.g., via particular instructionsincluded in the locate data algorithm 137 executing on the processor118, and/or various hardware modifications) to operate in multipledifferent modes so as to collect various information relating not onlyto a locate operation itself (locate information), but additionally (oralternatively) various information relating to the work site/dig area inwhich the locate operation is performed. For example, in oneimplementation, the locate receiver may be configured to operate in afirst “locate mode” which essentially follows various aspects of theprocess outlined in FIG. 6, and also operate in a second “landmarkidentification mode” (or more simply “landmark mode”), in which thelocate receiver acquires information relating to one or moreenvironmental landmarks that may be germane to the locate operation(e.g., in and around the work site/dig area and/or generally in thevicinity of the locate operation).

More specifically, in a “locate mode,” various locate information may becollected, logged, stored and/or transmitted, as discussed above, inconnection with the detection of a presence or absence of one or moreunderground facilities. Alternatively, in a “landmark mode,” atechnician positions the locate receiver proximate to an environmentallandmark of interest and, upon actuation of the locate receiver (e.g.,via an actuator or manipulation of a user interface control mechanism),the locate receiver collects various information about the landmark(hereafter referred to as “landmark information”), which information mayinclude, but is not limited to, geo-location data of an environmentallandmark, type of environmental landmark, and a time stamp for anyacquired information relating to an environmental landmark.

With respect to mode selection, the locate receiver may be configured(e.g., via execution of the locate data algorithm) to provide for modeselection in any of a number of manners. For example, in oneimplementation, the locate receiver may be equipped with a simpleswitch, referred to as a “mode selection switch,” which in someinstances may form part of the user interface 126. The switch mayinclude an open contact state and a closed contact state, wherein onecontact is electrically coupled to a power signal or to ground, andanother contact is electrically coupled to an input of the processor118; in this manner, when the switch is toggled, a mode signal may beprovided to the processor 118 as an interrupt event to indicate“landmark mode.” In response to the mode signal indicating landmarkmode, the processor 118 may request timing information from the timingsystem and log into an electronic record a “landmark mode event entry”including a landmark mode time stamp associated with the landmark modesignal. Additionally, or alternatively, the processor may respond to thelandmark mode signal by taking one or more other actions pursuant toexecution of a portion of the locate data algorithm 137 includingparticular instructions to implement the landmark mode, such asproviding for the selection of landmark categories and/or types (via theuser interface 126 and menus provided on the display 146), and loggingactuation event entries in an electronic record as “landmark evententries.”

Again, as noted above, such a mode selection switch may be provided bythe user interface 126, for example, in the form of a button, switch,portion of the touch screen display, microphone to provide forvoice-activation, etc. Apart from a hardware switch, the user interface126 alternatively may be employed for mode selection between locate modeand landmark mode; in particular, the user interface 126 and/or display146 may implement a menu-driven GUI to provide for mode selection.

FIG. 8 is a flow diagram of an exemplary process 800, according to oneembodiment of the present invention, for operating a locate receiverhaving a locate mode and a landmark mode so as to collect locateinformation and/or environmental landmark information during operationof the locate receiver, and generate an electronic record of suchinformation. Several aspects of the process 800 shown in FIG. 8 aresubstantially similar or identical to those discussed above inconnection with FIG. 6; in particular, blocks 602 through 614 are thesame in both FIGS. 6 and 8, and the blocks 616, 618, and 620 in FIG. 8are additional aspects of the process 800.

In the process 800 outlined in FIG. 8, following commencement of alocate operation the locate technician may utilize the user interface126 (e.g., press a button, operate a joy-stick, touch a touch screendisplay portion of a graphical user interface, speak into a microphoneto provide a voice-activated command, etc.) to not only pause, restart,and/or indicate completion of the locate operation, but further toselect a landmark mode of operation for the locate receiver. As notedabove in the discussion of FIG. 6, any one or more of these actions mayconstitute interrupt events. For example, as indicated in block 616 ofFIG. 8, if a technician selects “landmark mode” via the user interface,the user interface may provide a “landmark mode signal” to theprocessor. In response to this signal, the processor may request timinginformation from the timing system and log a “landmark mode event entry”including a landmark mode time stamp associated with the landmark modesignal. Additionally, or alternatively, the processor may respond to thelandmark mode signal by taking one or more other actions pursuant toexecution of a portion of the locate data algorithm 137 includingparticular instructions to implement the landmark mode (as discussedabove, the landmark mode may be entered in alternative implementationsvia a mode signal provided to the processor 118 by a dedicated modeselector switch.

Table 8 below provides an example of content and format for a modeselect event entry that may be logged in a file for an electronic recordand/or transmitted by the locate receiver. The example mode select evententry shown below in Table 8 follows a similar format to that used forthe event entry examples provided in Tables 2-5 above.

TABLE 8 Format INFO+MODE: (DATE) (TIME) (DEV_ID) (JOB_ID) (MODE)<CR><LF> Examples INFO+MODE: DATE(2009-04-15) TIME(12:03:44) DEV(2334)JOB(4000) (LANDMARK) <CR> <LF>

In the process outlined in FIG. 8, subsequent to selection of thelandmark mode, as noted in block 618 the process may provide for theselection of a particular category and/or type of landmark for whichinformation is to be collected. To this end, in one implementation theprocessor 118 controls the user interface 126 (including display 146) soas to display information to the technician to facilitate such aselection. In particular, a landmark selection submenu may be displayed,including one or more categories of landmarks displayed in any of avariety of manners (e.g., as a list of text entries, an arrangement oficons symbolizing respective categories, labeled symbols, etc.).Examples of landmark categories that may be displayed in such a submenuinclude, but are not limited to: 1) “Natural Gas;” 2) “Water/Sewer;” 3)“Power Line;” 4) “Phone Line;” 5) “CATV Line;” and 6) “Other.”

Upon selection via the user interface of one of the landmark categoriesdisplayed on the submenu, the processor may control the user interfaceso as to display yet another submenu indicating various types oflandmarks that fall within the selected category, so as to facilitateselection of a particular type of landmark for which information is tobe collected. Examples of types of landmarks that may be displayed andavailable for selection via the user interface, for each of the aboveidentified categories, include, but are not limited to:

-   -   Natural Gas: 1) Service Meter; 2) Manifold; 3) Test Station; 4)        Regulator Station; 5) Vent/Vent stack; 6) Valve; 7) Trace        Wire; 8) Anode; 9) Branch Service; 10) Capped Service; 11)        Compressor Station; 12) Farm Tap; 13) Service Regulator; 14)        Service Line; 15) Service Riser; 16) Shut Off Valve; 17)        Tee; 18) Valve Box; 19) Transmission Pipeline; 20)        Main/Distribution Main; 21) Offset; 22) Low Pressure; 23) Medium        Pressure; 24) High Pressure    -   Water/Sewer: 1) Transmission Main; 2) Water Main; 3) Manhole; 4)        Valve; 5) Clean out; 6) Sewer Lateral; 7) Water Meter; 8) Storm        Sewer 9) Sanitary Sewer; 10) Pump Station; 11) Tap; 12)        Faucet; 13) Fire Hydrant; 14) Tracer Wire    -   Power Line: 1) Pole; 2) Anchor; 3) Transformer; 4) Manhole; 5)        Handhole; 6) Street light; 7) Electrical Riser; 8) Primary; 9)        Secondary; 10) Switch; 11) Fused Switch; 12) Circuit        Breaker; 13) Duct; 14) Power Plant; 15) Transmission        Substation; 16) Power Substation; 17) Service Line; 18)        Meter; 19) Pedestal; 20) Switch Gear; 21) Switch Cabinet; 22)        Buried Transformer; 23) Riser; 24) Red Top Tracer    -   Phone Line: 1) Pole; 2) Anchor; 3) Manhole; 4) Handhole; 5)        Subscriber Line Carrier; 6) Digital Loop Carrier; 7) Remote        Terminal; 8) Cross Box; 9) Continual environment Vault; 10)        Fiber Optics; 11) Encapsulated Plant; 12) Building Terminal; 13)        Terminal; 14) Aerial; 15) Buried; 16) Underground; 17) Duct        Run; 18) Central Office; 19) Buried Joint; 20) Splice    -   CATV Line: 1) Pole; 2) Anchor; 3) Headend; 4) Manhole; 5)        Handhole; 6) Transmitter; 7) Fiber Transmitter; 8) Receiver; 9)        Fiber Receiver; 10) HUB Location; 11) Power Supply/Inserter; 12)        Fiber Node; 13) Amplifier; 14) Ped; 15) Dog House; 16)        Subscriber Service Line; 17) Trunk Station; 18) Trunk Line        Amplifier; 19) AC Power Supply Pedestal    -   Other: various natural, architectural, or infrastructure-related        landmarks, such as buildings, curbs, “tagged” curbs        (intentionally marked curbs that are likely to survive        excavation, to serve as points of reference to validate marking        operations), streets, driveways, property boundaries, trees and        other landscape elements, termination points of abandoned        facilities, etc.

While the foregoing discussion of landmark categories and types providesone construct in which a wide variety of landmarks are made availablefor selection by the technician, it should be appreciated that in otherimplementations, options for landmark selection may be presented indifferent manners. For example, a more succinct list of landmark typesmay be presented to the technician to facilitate easy selection (e.g., amore limited set of about a dozen more common landmark types that mightbe encountered in the field, such as “telephone pole,” “fire hydrant,”“meter,” “manhole,” “curb,” etc.). More generally, any number andvariety of landmark types may be presented to the technician via theuser interface in alphabetically ordered lists, numerically orderedlists, or other types of ordered text-based or symbolic arrangements,for example.

In another exemplary implementation, the categories and/or types oflandmarks made available for selection via the user interface may bebased at least in part on a type of facility being located when thelocate receiver was in a locate mode prior to selection of the landmarkmode. For example, consider a technician using the locate receiver inthe locate mode and in the process of locating a power line. In oneimplementation, upon switching to landmark mode, the user is firstpresented with selection options for landmark category and/or type thatare more closely related to a power line (e.g., a more limited subset ofoption types including “pole,” “transformer,” “pedestal,” etc.). In oneaspect, the technician may nonetheless still have the option to selectother categories and/or types of landmarks, but as a default thetechnician is first presented with options related to the type offacility last being located. In another aspect, the selection optionsfor landmark category and/or type may be specifically and intentionallylimited to those options that are most germane to the type of facilitylast being located in the previous locate mode (i.e., immediately priorto entry into the landmark mode).

In yet another exemplary implementation, the user interface may includea microphone and the processor may be configured to accept and processaudible commands, such that landmark category and/or type selection maybe accomplished via voice-activated commands. For example, once landmarkmode is selected, the technician may select a particular landmarkcategory or type by simply speaking into the microphone (e.g.,“telephone pole,” “fire hydrant,” “meter,” “manhole,” “curb,” etc.).

In addition to, or as an alternative to, selection of landmark categoryand/or type, block 618 may provide for the entry of any of a variety oftext information for inclusion as part of the landmark information in anelectronic record. For example, in some exemplary implementations, viathe user interface and/or display the technician may enter text-basedinformation relating to an environmental landmark (e.g., as an offset toanother topological, architectural, or infrastructure feature inproximity to the environmental landmark—“telephone pole 5 ft. from backof curb”). Additionally, in a manner similar to landmark type selection,the user interface/display may provide for menu-driven selection via aGUI of predetermined options for additional text-based information to beincluded as part of the landmark information (e.g., a set of “stock”text messages for selection to be included as part of landmarkinformation).

Following selection of landmark category and/or type, and/orentry/section of any text-based information in block 618 of the process800 shown in FIG. 8, in block 620 actuations of the actuator 142 inlandmark mode cause the processor to collect various “landmarkinformation” with each actuation, which information is logged in anelectronic record as a “landmark event entry” (rather than an actuationevent entry, as noted in Table 3 above). Essentially, in landmark mode,the technician positions the locate receiver proximate to a selectedcategory/type of landmark and actuates the actuator (or manipulates adesignated user interface control mechanism) to acquire variousinformation relating to the landmark (e.g., geo-location data, type,time stamp).

In general, the processor may be configured to communicate with (e.g.,poll) any of a variety of input devices to collect landmark informationto be logged in an electronic record. As discussed above in connectionwith the locate mode (refer again to FIG. 4), such information may beacquired from any of a variety of input devices including, but notlimited to, the location tracking system 130, the timing system 128, thecommunications interface 124 (e.g., a USB port or other port), the userinterface 126, and the local memory 122.

In particular, any data that is available from the location trackingsystem (e.g., any information available in various NMEA data messages,such as coordinated universal time, date, latitude, north/southindicator, longitude, east/west indicator, number and identification ofsatellites used in the position solution, number and identification ofGPS satellites in view and their elevation, azimuth and SNR values,dilution of precision values) may be collected as landmark informationand logged in an electronic record as part of a landmark event entry.Additionally, information collected from the user interface in the formof a text entry by the technician may be included in a landmark evententry; for example, in one implementation, upon actuation of theactuator, the processor may prompt the technician via the display of theuser interface to enter text notes, if desired (e.g., the technician maydescribe an offset of a target environmental landmark from anarchitectural, topographical, or infrastructure feature to complimentgeographic information provided by the location tracking system), andthis textual information may serve as landmark information. In view ofthe foregoing, it should be appreciated that “landmark information” mayinclude a wide variety of information components including, but notlimited to, one or more of geographical information (e.g., from thelocation tracking system), timing information (e.g., from the locationtracking system and/or the timing system), landmark category and/or typeinformation (e.g., selected or entered via the user interface), textualinformation (e.g., entered via the user interface), or other information(e.g., received from the local memory and/or the communicationsinterface).

Table 9 below provides an example of content and format for a landmarkevent entry that may be logged in a file for an electronic record and/ortransmitted by the locate receiver when in landmark mode. The examplelandmark event entry shown below in Table 9 also follows a similarformat to that used for the event entry examples provided in Tables 2-5above.

TABLE 9 Format INFO+LMRK: (DATE) (TIME) (GPS data) (CATEGORY,TYPE)(TEXT) <CR><LF> Examples INFO+LMRK: DATE(2009-04-15) TIME(12:04:44)GPS($GPGGA, 120443, 4807.038, N, 01131.000, E, 1, 08, 0.9, 545.4, M,46.9, M,, *47) LMRK(3, 12)(“Panel mounted rear wall of shed”)<CR><LF>

In the example landmark event entry given in Table 9, the landmarkinformation includes a time stamp (e.g., DATE and TIME), geographicalinformation (e.g., GPS data), category/type information, and text-basedinformation for an environmental landmark. The notation LMRK (3,12) inthe example denotes a category 3, type 12 landmark which, in theexemplary listings provided above, corresponds to “Power Line,” “CircuitBreaker.” It should be appreciated that the event entry shown in Table 9is provided primarily for purposes of illustration, and that a varietyof other or additional landmark information may be included in landmarkevent entries, as noted above.

As with the event entry examples provided in Tables 2-5 above, theexemplary format for a mode select and landmark event entry as shown inTables 8 and 9 may be included in either an ASCII and XML file formatfor an electronic record that is stored and/or transmitted by the locatereceiver (in which a particular naming scheme/format may be adopted toidentify files/electronic records, such as “ServerID_LocRecID_Job ID”).It should also be appreciated that an electronic record generated by amulti-mode locate receiver in some instances may include a mixture ofactuation event entries and landmark event entries, actuation evententries without any landmark event entries, and landmark event entrieswithout any actuation event entries.

Yet another alternative format for storing and organizing landmarkinformation in an electronic record, according to one embodiment of theinvention, is shown in Tables 10 and 11 below. By way of example, Table10 shows the format and content of an electronic record entry for autility pole, which includes one geo-location data point, and Table 11shows the format and content of an electronic record entry for apedestal, which includes four geo-location data points (i.e., one foreach corner of the pedestal). It should be appreciated that the formatand content shown below in Tables 10 and 11 is provided primarily forpurposes of illustration and, as noted above, a variety of format andcontent may be included in an electronic record entry for landmarkinformation. The examples provided in Tables 10 and 11 may constitute an“original” electronic record generated by the processor pursuant to theprocess 800 shown in FIG. 8, or may be derived from raw data collectedand logged pursuant to the process 800 (e.g., as a flat file, an ASCIIformatted file, or an XML formatted file) and subsequently reorganizedand particularly formatted. It should also be appreciated that theexamples provided in Tables 10 and 11 illustrate that landmarkinformation may be included in an electronic record together with one orboth of ticket information and service-related information, as discussedabove in connection with electronic records including various locateinformation.

TABLE 10 Example record of data acquired for a utility pole while inlandmark identification mode of operation Record Service provider ID0482 # 1 User ID 4815 Device ID 7362 Type of EL Type = utility poletimestamp data 12-Jul-2008; 09:35:17.5 geo-location data 2650.9256, N,08003.5234, W Other info (text entry) “5 ft. from back of curb” Locaterequest data Requestor: XYZ Construction Company, Requested serviceaddress: 222 Main St, Orlando, FL

TABLE 11 Example record of data acquired for a pedestal while inlandmark identification mode of operation Record Service provider ID0482 # 2 User ID 4815 Device ID 7362 Type of EL Type = pedestaltimestamp data 12-Jul-2008; 09:35:17.5 geo-location data 2650.9256, N,08003.5234, W Type of EL Type = pedestal timestamp data 12-Jul-2008;09:35:21.2 geo-location data 2650.9256, N, 08003.5226, W Type of EL Type= pedestal timestamp data 12-Jul-2008; 09:35:26.7 geo-location data2650.9288, N, 08003.5188, W Type of EL Type = pedestal timestamp data12-Jul-2008; 09:35:33.5 geo-location data 2650.9321, N, 08003.5177, WOther info (text entry) “7 ft from pavement edge” Locate request dataRequestor: XYZ Construction Company, Requested service address: 222 MainSt, Orlando, FL

FIG. 9 is a block diagram similar to FIG. 7 and illustrates an exemplarydata structure for an electronic record 135 that includes both locateinformation and landmark information (i.e., that may be generated byand/or based on information collected during the process 800 discussedabove in connection with FIG. 8 and based on the organization ofinformation shown in Tables 10 and 11 above). Like the exemplaryelectronic record shown in FIG. 7, the record 135 in FIG. 9 includes afile identifier 701 (e.g., one or more of Job ID, LocRecID, ServerID,etc.) and a plurality of actuation data sets 1 through N (with referencenumbers 702A, 702B, 702C . . . 702N), wherein each actuation data set isassociated with a corresponding actuation of a locate receiver. In FIG.9, also as in FIG. 7, additional details of the data structure foractuation data set 3 702C are shown, relating to locate informationcollected in locate mode. However, unlike FIG. 7, FIG. 9 shows that theactuation data set 2 702B relates to landmark information acquiredpursuant to an actuation in landmark mode; in particular, the actuationdata set 2 702B includes a date/time field 902, a type field 904, and ageo-location field 906 corresponding to a landmark event entry.

In other respects, the data structure in FIG. 9 is similar to that shownin FIG. 7. For example, various other information that may be common tomultiple (or all) actuation data sets of a given electronic record maybe stored in one or more additional elements of the electronic recordthat are not contained within one or more of the actuation data setsthemselves (e.g., one or more of the ticket information field 714, theservice-related information field 716, and the locate signal informationfield 710, which are shown as part of the data structure for a givenactuation data set of the electronic record, may instead be elements ofthe electronic record that are common to all actuation data sets of agiven electronic record).

Once an actuation of the locate receiver in landmark mode has beenlogged as a landmark event entry, the process 800 shown in FIG. 8returns to block 610. At this point, the technician is provided (via theuser interface/display) with the options of pausing the job (block 610),restarting the job if previously paused (block 612), stopping the joband indicating completion (block 614) or selecting landmark mode again(block 616) for the next actuation. If the technician selects none ofthese options, the process returns to block 608, at which point furtherpolling and/or interrupt events are logged, as discussed above inconnection with FIG. 6. Accordingly, after an actuation in landmarkmode, in one exemplary implementation the locate receiver defaults backto the locate mode, unless and until the technician selects the landmarkmode again for a subsequent actuation.

In an alternative implementation not shown in FIG. 8, followingactuation of the locate receiver in landmark mode, the processor maycontrol the user interface/display to provide an option to thetechnician to exit landmark mode (rather than automatically presentingthe options of pause job, restart job, stop job, or landmark mode). Inthis manner, the locate receiver remains in landmark mode for subsequentactuations until the technician makes a menu selection to exit landmarkmode, at which point the process 800 returns to block 610.

In yet another embodiment, the processor 118, executing locate dataalgorithm 137 in landmark mode, may be configured to generate anessentially continuous stream of data packets representing various evententries logged by the locate receiver (e.g., as shown above in Tables2-9). As discussed above in connection with the locate mode, each datapacket may include a header, one or more flag fields, and one or moreinformation payload fields. To accommodate both a locate mode and alandmark mode, one flag field may be set or reset upon selection of thelandmark mode so as to identify the contents of any information payloadfield in the data packet as landmark information as opposed to locateinformation. Similarly, as discussed above, one or more other flagfields may be set (or reset) upon occurrence of one or morepredetermined interrupt events (e.g., pull/depress actuator, releaseactuator, automatic logging of data, low power, communication link fail,etc.). In this manner, a continuous stream of data may be provided as anoutput by the processor, in which certain interrupt events, such as anactuation and/or release of the actuator, “tag” certain data packets viaan interrupt flag, and certain data packets also may be tagged asgenerated in locate mode or landmark mode. In yet other aspects of thisembodiment, all data packets thusly generated may be stored in the fileopened for the electronic record and/or transmitted from the locatereceiver in essentially real time; alternatively, only certain datapackets with one or more predetermined flags set may be stored and/ortransmitted.

Thus, in landmark identification mode, a locate technician may employ anappropriately configured locate receiver to capture the types andlocations of environmental landmarks of interest that are present at thework site and/or in the general environs of a dig area. While inlandmark mode, the locate technician may approach a certainenvironmental landmark, then select the type of the environmentallandmark via user interface, position the locate receiver (e.g., placethe tip of locate receiver) proximate to the target environmentallandmark, and then actuate the locate receiver. In doing so, the locatereceiver logs in an electronic record landmark information including,for example, the type of the target environmental landmark, thegeo-location of the target environmental landmark, and a time stamp inan electronic record. The locate technician may move from oneenvironmental landmark to the next until information about allenvironmental landmarks of interest has been captured. Additionally, oneor more data points (e.g., “landmark event entries”) may be captured forany given environmental landmark.

V. Computer-Generated Visual Representation of a Locate OperationIncluding Locate Information and Landmark Information

With reference again to FIGS. 4 and 5, in yet another embodiment theprocessor 118, executing locate data algorithm 137, and/or one or moreremote computers 150 executing locate data algorithm 137, mayadditionally process various locate information and/or landmarkinformation provided in real time from a locate receiver and/or storedin an electronic record of locate operation and control a display device(e.g., display 146 of locate receiver 110 or some other display device)to render a computer-generated visual representation of one or both ofthe locate information and landmark information. Such a visualrepresentation may be used, for example, to provide immediate feedbackto the locate technician, provide essentially real-time feedback to asupervisor monitoring the technician from a remote location, provide avisual record of the locate information and/or the landmark information(e.g., for archiving purposes, once one or more electronic records aregenerated), and/or to verify the quality (e.g., accuracy andcompleteness) of work performed during a locate and marking operation.For purposes of the following discussion, a “locate operation” may referto one or both of the processes of collecting locate information andlandmark information. Accordingly, it should be appreciated that invarious exemplary implementations of a computer-generated visualrepresentation, only locate information may be visually rendered, onlylandmark information may be visually rendered, or both locateinformation and landmark information may be visually rendered.

In various aspects of this embodiment, a visual representation may bestatic in that all available locate information and/or landmarkinformation is presented in a display field at one time after generationof an electronic record; alternatively, the visual representation may bedynamic in that locate information and/or landmark information isdisplayed in essentially real-time as it is collected, or may bedisplayed after generation of the electronic record in a time-sequencedanimation that “recreates” the collection of information on the timescale in which it was originally acquired (e.g., based on the timestamps indicating when the information was acquired).

In other aspects, the relative positions of one or more detectedfacilities, as represented by actuation event entries and/or interruptevent entries (e.g., representing automatically logged locateinformation) logged and/or transmitted by the locate receiver, as wellas the relative positions of all environmental landmarks represented bylandmark event entries logged and/or transmitted by the locate receiver,may be displayed (e.g., based on geo-location data and some appropriatescale of an available display field of display 146) to provide a visualrepresentation of the locate operation. A visual representation of alocate operation may also be rendered in one or more particular colorscorresponding to one or more particular underground facilities detectedduring the locate operation (e.g., see Table 7).

In one exemplary implementation, such a visual representation mayinclude one “electronic detection mark” displayed in a display field foreach actuation of a locate receiver. Alternatively, in another exemplaryimplementation of such a visual representation, an essentiallycontinuous solid line (or other line type) may be displayed in a displayfield to represent a given underground facility detected during a locateoperation. In another aspect, the processor may process the geo-locationdata in respective actuation data sets of an electronic record so as tofilter, average, interpolate and/or otherwise “smooth” data (e.g., so asto provide “cleaner” visual renderings and/or connect successiveelectronic detection marks represented by the respective actuation datasets of the electronic record); alternatively, “raw data” provided bythe locate receiver may be utilized for the visual representation. Inyet another aspect of this embodiment, visual representations ofmultiple locate operations for different underground facilities withinthe same work site/dig area may be generated in the same display fieldof a display device so as to provide a composite visual representation,in which different underground facilities may be uniquely identified insome manner (e.g., by different line types and/or different colors), andone or more environmental landmarks in and/or around the work site/digarea may be identified using a variety of displayed identifiers (e.g.,icons, symbols, marks, shapes, etc.).

FIG. 10 illustrates a flow chart for a process 850 according to oneembodiment of the present invention for generating a visualrepresentation of a locate operation based on an electronic recordand/or essentially real-time information transmission from the locatereceiver 110. As noted above, the process 850 may result from theexecution of various embodiments of the locate data algorithm 137 on theprocessor 118 of the locate receiver 110 (to render the visualrepresentation on the display 146 of the locate receiver), or by one ormore other remote computers (to render the visual representation on oneor more other display devices).

In block 802 of the process 850, if an electronic record has alreadybeen generated for the locate operation in which one or more undergroundfacilities are detected and/or environmental landmark information isacquired, the record is examined to determine the geographic extents ofthe electronic detection marks and/or environmental landmarks to bevisually rendered on a display device. In particular, the processor 118may review the geo-location data of all elements/actuation data sets ofthe electronic record to determine (e.g., based on the respectivelatitude and longitude coordinates of the available geo-location data)the maximum extents of the locate operation to be visually rendered.

The maximum extents of the locate operation may be determined in any ofa variety of manners according to different exemplary implementations.For example, in one exemplary implementation, in block 802 the processor118 may determine the centroid of all electronic detection marks and/orenvironmental landmarks represented by the data of the electronic recordto be displayed. The processor then determines the geographic extent ofthe collection of electronic detection marks and/or environmentallandmarks by determining one or more latitude/longitude coordinate pairsfrom the available data having a greatest distance from the centroid. Inone example, the processor may determine a single farthest point fromthe centroid, and a distance between this farthest point and thecentroid serves as a radius of a circle that provides an “extents areacircle.” In another example, the “farthest opposing corners” of arectangle around the centroid may be determined by assigning thecentroid as the origin of a reference coordinate system, and finding thecoordinate pairs in opposing quadrants of the coordinate system having agreatest distance from the centroid (e.g., the +LAT/+LONG and −LAT/−LONGcoordinate pairs at a greatest distance from the origin) to provide an“extents area rectangle.” Other types of polygons and closed shapes(ovals) may be employed to provide an extents area for the locateoperation to be displayed.

Alternatively, if an electronic record has not been previously generatedand information received in essentially real-time from the locatereceiver is to be displayed in a display field, a default extents areamay be selected in advance based on any of a variety of criteria. Forexample, address and/or site description information provided in aticket pursuant to which the locate operation is performed may provide abasis on which an extents area for the locate operation may be estimateda priori. Similarly, as discussed further below in connection with FIG.13, an available digital image of the work site/dig area may be employedto determine or estimate an initial extents area for the locateoperation.

In block 804, the extents area of the locate operation to be visuallyrendered is then mapped to an available display field of a displaydevice, using any appropriate scaling factor as necessary, to ensurethat all of the geo-location data in the electronic record fits withinthe display field. For example, in one exemplary implementation, atransformation may be derived using information relating to theavailable display field (e.g., a reference coordinate system using anappropriate scale for a given display field of a display device) to mapdata points within the extents area to the available display field. Inanother aspect of this example, a buffer area around the extents areamay be added to provide one or more suitable margins for the displayedvisual representation, and/or to accommodate different shapes of extentsareas to the available display field of the display device, and anappropriate transformation may be derived based on this optionaladditional buffer area.

Once a transformation is derived to map the locate operation extentsarea to the available display field of a display device, in block 806one or more electronic detection marks and/or one or more identifiers(e.g., icons, symbols, marks, shapes, etc.) for environmental landmarksis/are rendered in the display field based on applying thetransformation to the geo-location data present in the data set of theelectronic record (which in some instances may include one or moreactuation data sets). In one exemplary implementation, one electronicdetection mark is rendered in the display field for each actuation dataset of an electronic record. In one aspect, as discussed above, a givenelectronic detection mark may be rendered in a particular color and/orline type to represent a type of underground facility represented by themark.

FIG. 11 illustrates a plan view of an exemplary composite visualrepresentation 900 that “electronically recreates” a locate operationfor various underground facilities and environmental landmarks presentin a work site/dig area, based for example on the process 800 discussedabove in connection with FIG. 8. In particular, FIG. 11 illustrates anumber of electronic detection marks corresponding to actuations and/orautomatic logging interrupt events of a locate receiver whose relativepositions in the display field are derived from the correspondinggeo-location data in an electronic record, as discussed above. In theexample of FIG. 11, act-1 through act-7 form a lines pattern 910representing a first detected underground facility, act-8 through act-14form a lines pattern 912 representing a second detected undergroundfacility, act-15 through act-24 form a lines pattern 914 representing athird detected underground facility, and act-25 through act-34 form alines pattern 916 representing a fourth detected underground facility.FIG. 11 also includes identifiers for various environmental landmarksdisposed in proximity to the electronic detection marks; in particular,a building 950 is shown in the top portion of FIG. 11, whereas twoutility poles 952 and 954, as well as a fire hydrant 956, are shown inthe bottom portion of FIG. 11.

As noted above, while in one embodiment there may be a one-to-onecorrespondence between electronic detection marks rendered in a singleor composite visual representation and actuations/automatic data logginginterrupt events of a locate receiver, in yet other embodiments a singleor composite visual representation may provide a variety of otherindicators/digital representations of detected underground facilities ina computer-generated visual rendering. For example, FIG. 12 illustratesanother example of a composite visual representation 1000 based on thesame electronic record used to generate the composite visualrepresentation 900 of FIG. 11, in which continuous lines are used toindicate the respective locate operations. To this end, in one exemplaryimplementation, an additional step may be included in the process 800shown in FIG. 8, in which the processor may process the locategeo-location data in an electronic record by filtering, averaging,interpolating and/or otherwise “smoothing” the data (e.g., so as toconnect successive discrete detection marks represented by respectiveactuation data sets/event entries of the electronic record) and therebyprovide a substantially smooth continuous line for display.

Similarly, filtering, averaging, interpolating, processing and/orotherwise smoothing of data may be applied to landmark informationcaptured in landmark event entries. For example, multiple event entrieslogged for a particular environmental landmark (e.g., the four cornersof a pedestal) may be processed so as to provide a single point in adisplay field at which to display a symbol, icon or other identifier foran environmental landmark. Such processing may include, for example,selecting any one of multiple geo-location coordinates captured inmultiple event entries as representative of the landmark location,calculating a centroid of all points represented by capturedcoordinates, “pre-filtering” a collection of coordinates to eliminatesignificant “outliers” and subsequently determining a centroid of theremaining coordinates, etc.

In the example of FIG. 12, as also noted above, different undergroundfacility types may be indicated in different color lines, and thedifferent colors/facility types may be derived from the electronicrecord (e.g., based on the correlations provided in Table 7).Furthermore, in other aspects, text indicators may be included in thevisual representation, and/or other types of coding may be used(different line styles such as patterns, width, bold, etc.; a successionof symbols or other graphic icons, etc.) to indicate different facilitytypes, and/or some other aspect of a given facility (e.g., the materialused for a particular pipe, conduit, cable, sheathing; the diameter of aparticular pipe, conduit, cable; offsets to one or more environmentallandmarks, etc.). By way of example, FIG. 12 indicates that the fourunderground facilities in the composite visual representation correspondto a power line 1010 (which may be rendered in the color red), a firstsewer line 1012 (which may be rendered in the color green), a secondsewer line 1014 (which also may be rendered in the color green), and atelecommunications line 1016 (which may be rendered in the colororange). An exemplary composite visual representation may includeadditional textual, numeric and/or graphic elements to provide otherinformation available in the electronic record for the locate operations(e.g., timestamp information, ID information, coordinates for locationinformation, offset indications, etc.). For example, in FIG. 12 anoffset 958 of 3 feet is indicated between the fire hydrant 956 and thesewer line 1014.

In yet another embodiment, a single or composite visual representationof a locate operation, including one or both of locate information andlandmark information, may be rendered on a display device together witha digital image representative of at least a portion of a dig area at awork site, such that one or more electronic detection marks and/or oneor more identifiers for environmental landmarks appear in appropriaterelative positions overlaid on the displayed digital image. FIG. 13illustrates yet another example of a composite visual representation1100, albeit based on an electronic record different than that used togenerate the visual representations of FIGS. 11 and 12, in whichcontinuous lines are used to indicate the respective differentunderground facilities detected, and these lines are overlaid on adigital image of a dig area, together with identifiers for environmentallandmarks. It should be appreciated that although continuous linesrepresenting underground facilities are depicted on a digital image inFIG. 13, in other embodiments discrete electronic detection markscorresponding to successive actuations/automatic logging interruptevents of the locate receiver may be overlaid on a digital image of thedig area.

In the embodiment of FIG. 13, a number of different image sources andimage types may be employed to provide the digital image on which avisual representation of a locate operation may be overlaid. Forpurposes of the present disclosure, such a digital image (also referredto herein as an “input image”) may be any image represented by sourcedata that is electronically processed (e.g., the source data is in acomputer-readable format) to display the image on a display device. Aninput image may include any of a variety of paper/tangible image sourcesthat are scanned (e.g., via an electronic scanner) or otherwiseconverted so as to create source data (e.g., in various formats such asXML, PDF, JPG, BMP, etc.) that can be processed to display the inputimage. An input image also may include an image that originates assource data or an electronic file without necessarily having acorresponding paper/tangible copy of the image (e.g., an image of a“real-world” scene acquired by a digital still frame or video camera orother image acquisition device, in which the source data, at least inpart, represents pixel information from the image acquisition device).

In some exemplary implementations, input images according to the presentdisclosure may be created, provided, and/or processed by a geographicinformation system (GIS) that captures, stores, analyzes, manages andpresents data referring to (or linked to) location, such that the sourcedata representing the input image includes pixel information from animage acquisition device (corresponding to an acquired “real world”scene or representation thereof), and/or spatial/geographic information(“geo-encoded information”).

In view of the foregoing, various examples of input images and sourcedata representing input images according to the present disclosure, towhich the inventive concepts disclosed herein may be applied, includebut are not limited to:

-   -   Manual “free-hand” paper sketches of the geographic area (which        may include one or more buildings, natural or man-made        landmarks, property boundaries, streets/intersections, public        works or facilities such as street lighting, signage, fire        hydrants, mail boxes, parking meters, etc.);    -   Various maps indicating surface features and/or extents of        geographical areas, such as street/road maps, topographical        maps, military maps, parcel maps, tax maps, town and county        planning maps, call-center and/or facility polygon maps, virtual        maps, etc. (such maps may or may not include geo-encoded        information);    -   Facility maps illustrating installed underground facilities,        such as gas, power, telephone, cable, fiber optics, water,        sewer, drainage, etc. Facility maps may also indicate        street-level features (streets, buildings, public facilities,        etc.) in relation to the depicted underground facilities.        Examples of facility maps include CAD drawings that may be        created and viewed with a GIS to include geo-encoded information        (e.g., metadata) that provides location information (e.g.,        infrastructure vectors) for represented items on the facility        map;    -   Architectural, construction and/or engineering drawings and        virtual renditions of a space/geographic area (including “as        built” or post-construction drawings);    -   Land surveys, i.e., plots produced at ground level using        references to known points such as the center line of a street        to plot the metes and bounds and related location data regarding        a building, parcel, utility, roadway, or other object or        installation;    -   A grid (a pattern of horizontal and vertical lines used as a        reference) to provide representational geographic information        (which may be used “as is” for an input image or as an overlay        for an acquired “real world” scene, drawing, map, etc.);    -   “Bare” data representing geo-encoded information (geographical        data points) and not necessarily derived from an        acquired/captured real-world scene (e.g., not pixel information        from a digital camera or other digital image acquisition        device). Such “bare” data may be nonetheless used to construct a        displayed input image, and may be in any of a variety of        computer-readable formats, including XML);    -   Photographic renderings/images, including street level,        topographical, satellite, and aerial photographic        renderings/images, any of which may be updated periodically to        capture changes in a given geographic area over time (e.g.,        seasonal changes such as foliage density, which may variably        impact the ability to see some aspects of the image); and    -   An image, such as any of the above image types, that includes        one or more dig area indicators that provide one or more        indications of or graphically delimit a dig area, as described        in U.S. patent application Ser. No. 12/366,853, published as        U.S. Patent Publication No. 2009-0238417-A1, incorporated by        reference herein. The virtual white lines may include lines,        drawing shapes, shades, symbols, coordinates, data sets, or        other indicators that are added to an image, and may assist a        locate technician in the performance of a locate operation by        identifying the area of interest, i.e., the dig area. In this        manner, a searchable electronic record according to the concepts        disclosed herein may be generated based on a previously        marked-up input image on which the dig area is indicated.

It should also be appreciated that source data representing an inputimage may be compiled from multiple data/information sources; forexample, any two or more of the examples provided above for input imagesand source data representing input images, or any two or more other datasources, can provide information that can be combined or integrated toform source data that is electronically processed to display an image ona display device.

As noted above, in some implementations an input image may be indexed toGlobal Positioning System (GPS) coordinates or another coordinate systemthat provides geo-spatial positioning. An input image may includegeo-coding or other geographical identification metadata and may beprovided in any computer-readable format. An input image may alsoinclude images of map symbols, such as roads and street names, that maybe superimposed upon or displayed separately from an underlyinggeographic area when the input image is displayed on a display device.

Based on the foregoing, a digital image may be displayed in an availabledisplay field of a display device either before or after electronicdetection marks and/or identifiers for environmental landmarks aredisplayed in the available display field. For example, in oneimplementation, after the block 806 in FIG. 10, all or a portion of thedigital image may be mapped to the available display field based on anyrelevant geographic information accompanying the digital image (e.g.,GPS coordinates to which the image is indexed). Alternatively, thedigital image may be mapped first to the available display field of thedisplay device depending on appropriate scaling and/or transformationparameters as would be readily appreciated by one of ordinary skill inthe art, and thereafter one or more electronic detection marks and/orone or more identifiers for environmental landmarks similarly may bemapped to the available display field in appropriate positions relativeto the underlying digital image. In the example of FIG. 13, a firstvisual representation of a gas line 1130 is depicted, a second visualrepresentation of a communication line 1120 is depicted, and a thirdvisual representation of an electric line 1110 is depicted on an aerialimage of a residential dig area for purposes of illustration. Asdiscussed above in connection with other embodiments, these visualrepresentations may be displayed in different colors and/or line typesto denote different types of underground facilities and/or variousattributes of a given facility. As also illustrated in FIG. 13, othertypes of features may be included as part of the displayed image,including various environmental landmarks such as junction boxes ortransformers 1140, streets, property boundaries, tie-downs (referencelines between detected and/or marked facilities and environmentallandmarks and/or property boundaries) and their associated dimensions,and one or more text boxes 2173 (e.g., to indicate an address of thework site over the residence), and the like.

In some implementations, locate information and landmark information, ifdisplayed together, may be differentiated in a display field in any of avariety of manners (e.g., different line types, symbols or patterns;different colors or shades of related colors; artificially offset fromeach other in the display field if locate information and landmarkinformation overlap or are sufficiently close to each other in someinstances, etc.) to allow for sufficient visual perception of bothlocate information and landmark information.

Additionally, in one embodiment, each of locate information and landmarkinformation, if present in a computer-aided visual rendering, as well asany constituent information forming part of the locate information andlandmark information, may be displayed as separate “layers” of thevisual rendering, such that a viewer of the visual rendering may turn onand turn off displayed information based on a categorization of thedisplayed information. FIG. 14 shows a generic display device 3000having a display field 3005 with exemplary content for purposes ofexplaining some concepts germane to display layers, according to oneembodiment. For example, all locate information may be categorizedgenerally under one layer designation 3030 (“locate layer”) andindependently enabled or disabled for display accordingly, and alllandmark information may be categorized generally under yet anotherlayer designation 3040 (“landmark layer”) and independently enabled ordisabled for display accordingly. Respective layers may be enabled ordisabled for display in any of a variety of manners; for example, in oneimplementation, a “layer directory” or “layer legend” pane 3010 may beincluded in the display field 3005 (or as a separate window selectablefrom the display field of the visual rendering), showing all availablelayers, and allowing a viewer to select each available layer to beeither displayed or hidden, thus facilitating comparative viewing oflayers.

Furthermore, any of the above-mentioned general categories for layersmay have sub-categories for sub-layers, such that each sub-layer mayalso be selectively enabled or disabled for viewing by a viewer. Forexample, under the general layer designation of “locate layer,”different facility types that may have been detected during a locateoperation (and indicated in the locate information by color, forexample) may be categorized under different sub-layer designations(e.g., designation 3032 for “locate layer—electric;” designation 3034for “locate layer—gas;” etc.); in this manner, a viewer may be able tohide only the electric locate information while viewing the gas locateinformation, or vice versa, in addition to having the option to view orhide all locate information. Sub-layer designations similarly may beemployed for the landmark information (e.g., designation 3042 for“landmark layer—water/sewer;” designation 3044 for “landmarklayer—CATV;” designation 3046 for “landmark layer—buildings”). As shownin the example of FIG. 14, both the locate and landmark layers areenabled for display; amongst the illustrated sub-layer designations,only the “electric” sub-layer of the locate layer is enabled fordisplay, and only the “buildings” sub-layer of the landmark layer isenabled for display. Accordingly, using the exemplary composite visualrepresentation 1000 shown in FIG. 12 as a baseline for purposes ofillustration, only the power line 1010 appears in the electronicrendering 1000A shown in FIG. 14 as a constituent element of theelectric sub-layer of the locate layer, together with the building 950.

Virtually any characteristic of the information available for displaymay serve to categorize the information for purposes of display layersor sub-layers. In particular, any of the various exemplary constituentelements of locate information discussed herein (e.g., timinginformation, geographic information, service-related information, ticketinformation, target object information, locate signal information,locate receiver information, transmitter information, environmentalinformation, and operational information, the latter two of which arediscussed in greater detail further below) may be categorized as asub-layer, and one or more sub-layers may further be categorized intoconstituent elements for selective display (e.g., as sub-sub-layers).Similarly, any of the various exemplary constituent elements of landmarkinformation discussed herein (e.g., geo-location data of anenvironmental landmark, type of environmental landmark, a time stamp forany acquired information relating to an environmental landmark) may becategorized as a sub-layer (and any sub-layer may be further categorizedinto sub-sub-layers, and so on).

It should further be appreciated that, according to various embodiments,the attributes and/or type of visual information displayed as a resultof selecting one or more layers or sub-layers is not limited. Inparticular, visual information corresponding to a selected layer orsub-layer may be electronically rendered in the form of one or morelines or shapes (of various colors, shadings and/or line types), text,graphics (e.g., symbols or icons), and/or images, for example. Likewise,the visual information corresponding to a selected layer or sub-layermay include multiple forms of visual information (one or more of lines,shapes, text, graphics and/or images).

As a non-limiting illustrative example, a “target object” sub-layer of a“locate” layer may include respective sub-sub-layers of differentfacility types detected, in which respective facility types are renderedon the display as lines having different colors, line types and/orshading. A “locate signal” sub-sub-sub-layer of a facility typesub-sub-layer of a “target object” sub-layer may include respectivesub-sub-sub-sub-layers of different signal characteristics (e.g.,frequency, amplitude, phase, gain), in which different signal values arerendered on the display as text (e.g., in proximity to the visualrendering of the detected facility line of the corresponding type).Similarly, a “temperature” sub-layer of a “locate” layer may includeground temperatures sensed during detection of respective facilitylines, in which sensed temperatures are rendered on the display as anicon/symbol in combination with text (e.g., a snowflake accompanied by atext label “15 deg. F.”) in proximity to the visual rendering of thedetected facility line. From the foregoing, it may be appreciated that awide variety of information may be categorized in a nested hierarchy oflayers, and information included in the layers may be visually rendered,when selected/enabled for display, in a variety of manners.

In addition to the locate information and/or the landmark information,in yet other embodiments in which a digital image is rendered in thedisplay field (e.g., as shown in FIG. 13), the image information onwhich the digital image is based may be categorized as its own displaylayer, such that the locate information, landmark information, and imageinformation may be selectively enabled or disabled for display as adisplay layer. In this manner, the displayed digital image on which oneor both of locate information and landmark information may be overlaid(and in some instances constituent elements thereof) may be toggled onand off conveniently for comparative display.

In one exemplary implementation, all image information may becategorized generally under one layer designation (e.g., “Reference”—seedesignation 3050 in FIG. 14), and independently enabled or disabled fordisplay (e.g., hidden) accordingly. Similarly, while not shown in FIG.14, in some implementations all information available for overlay,including both locate information and landmark information if available,may be categorized generally under another layer designation (e.g.,“Field”) and independently enabled or disabled for display; accordingly,it should be appreciated that in one aspect of this alternativeimplementation, under the general layer designation of “Field,” thelocate information may be categorized as one sub-layer of the Fieldlayer (in some cases with additional associated locate sub-sub-layers)and the landmark information may be categorized as another sub-layer ofthe Field layer (in some cases with additional associated landmarksub-sub-layers).

Like the “Field” layer, the “Reference” layer similarly may have one ormore sub-layers for various constituent elements of the imageinformation upon which the digital image is rendered. Virtually anynumber of possible sub-layers may be accordingly designated, based atleast on the various examples of image information discussed above(e.g., maps, such as road maps or facilities maps; dig area indicators,either alone or forming part of a digital image; grids, either alone orforming part of a digital image; engineering or architectural drawings;photographic renderings; etc.—any of which may have constituent elementsof information that respectively may be categorized as sub-sub-layers).To provide illustrative non-limiting examples of sub-layers of the“Reference” layer, FIG. 14 indicates a “digital image” sub-layer withthe designation 3052, a “dig area indicator(s)” sub-layer with thedesignation 3054, and a “grid” sub-layer with the designation 3056.

The various examples of visual representations illustrated in FIGS.11-14 may be used for various purposes, including, but not limited to:

-   -   (1) The display may be viewed by the locate technician for        substantially immediate feedback of his/her work performed,        which can be compared against the ticket information to ensure        that the full scope of the current locate operation has been        completed satisfactorily.    -   (2) The display may be viewed by a supervisor (using remote        computer 150 that is receiving the data) as substantially        immediate feedback of work performed by the locate technician,        which again can be compared against the ticket information to        ensure that the full scope of the current locate operation has        been completed satisfactorily. When the supervisor is viewing        the locate operation in real time, he/she may contact the locate        technician in real time in the event that the locate operation        is unsatisfactory;    -   (3) The display may be viewed by a quality control supervisor        (using remote computer 150 that has received the data) as        feedback of work performed by the technician, which again can be        compared against the ticket information to ensure that the full        scope of the current locate operation has been completed        satisfactorily. By viewing the locate operation, the quality        control supervisor may dispatch a quality control technician or        other personnel in the event that the locate operation is        unsatisfactory, and    -   (4) The display may be viewed by a training supervisor as        feedback of work performed by the locate technician, which can        be used to assess employee performance and direct training        activities.

VI. Environmental and Operational Sensors, and Information DerivedTherefrom

According to another aspect of the present invention, a locate receiver(or other locate device, e.g., a locate transmitter) includes one ormore environmental and/or operational sensors, which constituteadditional examples of input devices from which locate information maybe derived. In particular, one or more environmental sensors associatedwith a locate receiver may provide a variety of environmentalinformation in connection with use of the locate receiver; similarly,one or more operational sensors associated with the locate receiver mayprovide a variety of operational information in connection with use ofthe locate receiver. One or both of such environmental information andoperational information may constitute all or a portion of locateinformation and may be employed in any of the manners described above inconnection with locate information. In particular, environmentalinformation and/or operational information may be logged/stored in localmemory of a locate receiver, transferred to and stored in internetaccessible memory, formatted in various manners, processed and/oranalyzed at the locate receiver itself, and/or transmitted to anotherdevice (e.g., a remote computer/server, an internet storage site,cellular telephone, personal digital assistant (PDA), etc.) for storage,processing and/or analysis.

As used herein, environmental sensors are those which sense somecondition of the environment in which the locate receiver is present,but need not sense a condition of the locate receiver itself. Examplesof environmental conditions which may be sensed include, but are notlimited to, temperature, humidity, light, and altitude, among others.Environmental sensors may be included with the locate receiver for oneor more of various reasons. For example, information provided by one ormore of the environmental sensors may be used to assess whether a locateoperation was or is being performed in suitable environmental conditions(e.g., within accepted environmental tolerances). Additionally oralternatively, information provided by one or more environmental sensorsmay be used to interact with the technician operating the locatereceiver, for example by issuing a notification or warning signal to thetechnician if the sensed environmental condition is outside of anacceptable range (i.e., out of tolerance). Also, the information fromthe environmental sensor(s) may trigger an action or alteration of thelocate receiver, such as activating, enabling or disabling a particularcomponent of the locate receiver. Additionally or alternatively,information provided by one or more environmental sensors may augmentother information collected by the locate receiver, such as any of thetypes of information described above as being collected by a locatereceiver according to various embodiments herein. In some instances,information from two or more of the environmental sensors may be used incombination, examples of which are described in detail below.

As used herein, operational sensors are those which sense some operatingcondition of the locate receiver. Examples of such conditions include,but are not limited to, the angle of inclination of the locate receiver,the direction or heading of the locate receiver, a pressure applied tothe locate receiver, and/or some characteristic of motion of the locatereceiver (e.g., the speed at which the locate receiver is moving, theacceleration of the locate receiver, etc.), among others. Operationalsensors may be included with the locate receiver for one or more ofvarious reasons. For example, information provided by one or more of theoperational sensors may be used to assess whether a locate receiver wasor is operating appropriately during a marking operation or whether thelocate receiver was or is being operated (e.g., both electronicallyand/or physically manipulated) appropriately by the technician (e.g.,within accepted tolerances or according to protocols). Additionally oralternatively, information from one or more operational sensors may beused to detect patterns of operation of the technician, such astechnician “signatures” in using/manipulating the locate receiver (e.g.,characteristic movements unique to the technician). Additionally oralternatively, information from one or more operational sensors may beused to interact with the technician, for example by issuing anotification or warning signal to the technician in response to thedetected operational characteristic falling outside of an acceptablerange. Also, the information from the operational sensor(s) may triggeran action or alteration of the locate receiver, such as activating,enabling or disabling a particular component of the locate receiver.Additionally or alternatively, information provided by one or moreoperational sensors may augment other information collected by thelocate receiver, such as any of the types of information previouslydescribed herein in connection with other embodiments. Other uses ofdata provided by one or more operational sensors are also possible andcontemplated in the various aspects described herein. In some instances,information from two or more operational sensors may be used incombination, examples of which are described below. Furthermore,information from one or more operational sensors may be used incombination with information from one or more environmental sensors, asalso described further below.

It should be appreciated that some of the sensors described herein maybe considered both environmental and operational sensors, either becausethe sensor senses both an environmental condition and an operatingcondition of the locate receiver (i.e., the sensor senses more than onecondition) or because a single condition sensed by the sensor may beconsidered both an environmental condition and an operating condition.For example, an image capture device may be considered both anenvironmental sensor (e.g., the image capture device may capture animage of the surrounding environment) and an operational sensor (e.g.,the image capture device may capture an image of some action thetechnician has taken, for example, an image of the manner in which thetechnician is holding the locate receiver). Furthermore, the operationof a sensor may change over time. For example, a sensor may beconfigured at one time to measure an internal operating temperature andat a different time to measure an outside ambient temperature. Thus, itshould be appreciated that while the sensors described below arecategorized generally as being either environmental or operational forpurposes of illustrating some exemplary implementations, the categoriesare not mutually exclusive, and such categorization is not limitingunless otherwise stated.

FIG. 15 is a functional block diagram of a data acquisition systemincluding a locate receiver with both environmental sensors andoperational sensors, according to one embodiment of the presentinvention. As previously mentioned, a locate transmitter may likewiseinclude environmental and/or operational sensors, although the followingdiscussion focuses on locate receivers for purposes of illustration. Asshown in FIG. 15, the data acquisition system 1500 includes a locatereceiver 1510 and the previously described remote computer 150. Thelocate receiver 1510 comprises control electronics 112, power source114, and detection electronics 131, all of which also have beendescribed above in connection with other embodiments. The locatereceiver 1510 also comprises a light source 1532, and one or both ofenvironmental sensors 1520 and operational sensors 1530. It should beappreciated that while both environmental sensors 1520 and operationalsensors 1530 are shown in the locate receiver 1510, locate receiversaccording to other embodiments contemplated by the present disclosureneed not necessarily include both environmental sensors and operationalsensors.

With respect to environmental sensors, non-limiting examples of suitableenvironmental sensors include a temperature sensor (e.g., one or more ofan ambient temperature sensor and a surface temperature sensor (e.g., atemperature sensor for sensing a temperature of a surface toward whichthe locate receiver is pointed or oriented)), a humidity sensor, a lightsensor, an altitude sensor, an image capture device (e.g., a camera),and an audio recorder. This list is not exhaustive, however, as othertypes of environmental sensors may be included as appropriate to sensevarious environmental conditions of interest.

FIG. 16 is a block diagram showing details of the environmental sensors1520 shown in FIG. 15, according to one embodiment of the presentinvention. In FIG. 16, the illustrated environmental sensors 1520include an ambient temperature sensor 1602, a surface temperature sensor1604, a humidity sensor 1606, a light sensor 1608, an altitude sensor1609, an image capture device 1610, and an audio recorder 1612.Additional or alternative environmental sensors may be included, and oneor more of the illustrated environmental sensors may be omitted, in someembodiments. The environmental sensors may be coupled to the processor118 to receive control signals from the processor 118 and/or to providetheir respective outputs (e.g., signals, data, information) to theprocessor 118, and, as described further below, may operate in one ofvarious suitable manners. Information provided by any of theenvironmental sensors may be stored in local memory 122, for example asan electronic record 1802, described below, and/or transmitted to anexternal device, such as the remote computer 150, remote storage, etc.

The ambient temperature sensor 1602 may be configured to sense theambient temperature in the vicinity of the locate receiver 1510. Theambient temperature may be a useful piece of information, for example indetermining whether the temperature is adverse to performance of thelocate operation, which may occur when the temperature is too hot or toocold. For example, in some embodiments, it may be preferable to operatethe locate receiver only within a predetermined ambient temperaturerange between 20° F. and 110° F., although other ranges are possible. Inaddition, as described further below, the ambient temperature may beuseful in combination with one or more other types of environmentallysensed inputs, such as humidity, in evaluating the conditions in which alocate operation is performed.

The ambient temperature sensor may be any suitable temperature sensor,such as an infrared sensor, and may be an analog or digital temperaturesensor, as the various aspects described herein relating to a locatereceiver including an ambient temperature sensor are not limited tousing any particular type of temperature sensor. According to oneembodiment, the temperature sensor may be part of a combined temperatureand humidity sensor, such as the HS-2000V from Precon of Memphis, Tenn.In some embodiments, the ambient temperature sensor may be suitable tooperate between −40° F. and 125° F., or over any other suitable range,which in some embodiments may encompass the expected temperatures towhich the locate receiver may be exposed during normal operation. Thedata output by the ambient temperature sensor 1602 may be stored inlocal memory 122 and/or may be transmitted to an external device, suchas remote computer 150, in those embodiments in which the locatereceiver 1510 is communicatively coupled to the external device.

The surface temperature sensor 1604 may be configured to sense thetemperature of the surface toward which the locate receiver is pointingor oriented (e.g., the ground under the locate receiver). Thetemperature of the surface may be useful information for variousreasons. Thus, as a non-limiting example, information from the surfacetemperature sensor 1604 may be used to assess whether the locateoperation was or is being performed in such recommended temperatureconditions. As with the ambient temperature sensor 1602, the informationprovided by the surface temperature sensor 1604 may be stored in localmemory 122 and/or transmitted to an external device, such as the remotecomputer 150.

The surface temperature sensor 1604 may be any suitable type of sensorfor determining surface temperature, such as an infrared temperaturesensor or any other suitable type of temperature sensor. In someembodiments, the surface temperature sensor may be configured to operateacross a range of temperatures encompassing all expected surfacetemperatures to be encountered during normal operation of the locatereceiver. For example, in one embodiment the surface temperature sensormay operate between −40° F. and 125° F., although other temperatureranges are also possible.

The humidity sensor 1606 may be configured to sense the humidity of theenvironment in which the locate receiver 1510 is used, and in someembodiments may provide a relative humidity measurement (e.g., 0% to100% humidity). Such information may be useful alone or in combinationwith other information in determining whether, for example, theenvironment is too humid for performance of the locate operation. Thehumidity information provided by humidity sensor 1606 may be used toassess whether a locate operation was or is being performed withinacceptable humidity tolerances. The humidity sensor may be any suitabletype of humidity sensor, as the type is not limiting. According to oneembodiment, the humidity sensor may be part of a combined temperatureand humidity sensor, such as the HS-2000V from Precon of Memphis, Tenn.The information provided by the humidity sensor 1606 may be stored inlocal memory 122 and/or transmitted to an external device, such as theremote computer 150.

The light sensor 1608 may be configured to sense the intensity, flux, orilluminance of ambient light in the vicinity of the locate receiver1510. Such information may be useful, for example, to assess whether alocate operation was or is being performed in suitable lightingconditions (e.g., whether there was sufficient light to allow foraccurate performance of a locate operation, whether the area surroundingthe locate operation is sufficiently lit to ensure worker safety, etc.).The light sensor 1608 may be any suitable type of light sensor. In oneembodiment, the light sensor is a cadmium sulfide (CdS) photocell, whichis a photoresistor device whose resistance decreases with increasingincident light intensity. Such a device may provide a resistance orvoltage measurement as its output indicative of measured flux. However,other types of light sensors may alternatively be used. One non-limitingexample of a suitable photocell is the PDV-P5001 from Advanced Photonix,Inc. of Ann Arbor, Mich.

The units output by the light sensor may depend on whether the lightsensor is sensing light intensity, light flux, or illuminance. Forexample, the output may be in candela for light intensity, lumen forflux, or lux for illuminance. According to one embodiment, target valuesfor illuminance for accurate performance of a marking operation may bebetween approximately 1,000 lux and 100,000 lux, although other rangesmay be appropriate based on a particular location and type of locateoperation being performed. According to one embodiment, the output maybe converted to a percentage between 0% and 100%, for example in which0% corresponds to darkness and 100% corresponds to full sunlight. Otheroutputs may alternatively be produced. The information provided by thelight sensor 1608 may be stored in local memory 122 and/or transmittedto an external device, such as the remote computer 150.

According to one embodiment, the locate receiver further comprises alight source 1532, such as a flashlight or light emitting diode (LED)torch. The light source 1532 may be activated manually (e.g., by thetechnician) or may be coupled to the light sensor 1608 (e.g., directlycoupled or coupled through one or more components, such as processor118) and activated automatically in response to the light sensor sensingan unsatisfactorily low lighting condition (e.g., by receiving a signalfrom the processor 118 or by directly receiving an output signal of thelight sensor). The threshold light level for such automatic activationmay be any suitable level, non-limiting examples of which include anylevel at which the technician may have difficulty seeing and thereforeperforming the locate operation, and any predetermined level below whichtechnician safety may be comprised. Information about such activation ofthe light source (e.g., the occurrence of the activation, the time ofactivation, the duration, etc.) may be stored in local memory 122 and/ortransmitted to an external device, such as the remote computer 150.

The altitude sensor 1609 may be configured to measure the altitude ofthe locate receiver 1510, and may be any suitable type of altitudesensor for doing so. The altitude at which a locate operation isperformed may impact the performance of the locate operation and workersafety, among other considerations. Thus, information about the altitudemay be useful for a variety of reasons.

The output of the altitude sensor 1609 may be in any suitable units, andin some embodiments provides an altitude with respect to sea level. Forexample, the altitude sensor may provide an altitude in meters, miles,feet, or any other suitable units. The information provided by thealtitude sensor 1609 may be stored in local memory 122 and/ortransmitted to an external device, such as the remote computer 150.

The image capture device 1610 may be positioned on the locate receiverto capture an image of the environment surrounding the locate receiver1510 or may be configured or configurable in any suitable manner tocapture any type of image of interest. According to one embodiment, atechnician may be meant to take a picture of a job site and/or of anenvironmental landmark at the job site. Thus, inclusion of an imagecapture device 1610 in the locate receiver 1510 may facilitatecompliance with such protocols.

The image capture device 1610 may be capable of taking still images,video images, or both, as the various aspects described herein relatingto locate receivers including an image capture device are not limited inthis respect. Thus, the image capture device 1610 may be any suitabletype of image capture device, and in some embodiments may be a type thatis suitable for use in a portable device, such as, but not limited to,the types of digital cameras that may be installed in portable phones,wide angle digital cameras, 360 degree digital cameras, infrared (IR)cameras, and the like. In some implementations, a wide angle lens andautomatic zoom may be utilized to maximize the coverage area of eachimage.

The output of the image capture device may include various information.The output may include all or part of a captured image. Additionally oralternatively, the output may include information about the settingsand/or operation of the image capture device, such as any one or more ofresolution, frame rate (for video images), flash status (i.e., flashused or not used), image size, video sequence duration, zoom setting,etc.

In those embodiments in which the image capture device is a digitaldevice, the images may be stored in local memory 122 and/or transmittedto an external device, such as the remote computer 150. The images maybe in any standard or proprietary image file format (e.g., JPEG, TIFF,BMP, etc.). Furthermore, the images may be associated with a specificjob, a geographic position, and an exact time, in some embodiments, forexample by flagging the image based on the time at which it was taken,the location at which it was taken, and/or the job during which it wastaken. In one embodiment, each captured image may be cached andtransmitted with all other captured data from one or more othersensors/input devices.

The environmental sensors 1520 may further comprise an audio recorder1612, which may be used to capture audio input from a technician and/orfrom the environment (e.g., sounds in the vicinity of the locatereceiver). Thus, in one embodiment, the technician may, for example,dictate notes relating to the performance of the locate operation, suchas describing visible landmarks in the area of the locate operation,notes about performance of the locate receiver, or any other notes whichmay be relevant to performance of a locate operation. In one embodiment,the audio recorder may record sounds from the environment, such aspassing cars, planes, etc. Such recordings may be useful, for example,in assessing whether a technician was at the intended location of thelocate operation. For example, if a passing train is evident from therecording and the intended location is not near a train track, therecording may provide evidence that the technician was in the wronglocation.

The audio recorder 1612 may be an analog or digital device or devices.For example, in one embodiment the audio recorder 1612 may be an analogrecorder configured to receive an analog input signal (e.g., from amicrophone) and store the analog signal. According to anotherembodiment, the audio recorder 1612 may be a digital audio recorder,including any suitable combination of components for receiving an analogsignal (e.g., from a microphone), converting the analog signal to adigital signal, performing any suitable digital signal processing (e.g.,filtering, amplifying, converting to text, etc.) and storing the digitalinformation. According to one embodiment, the audio recorder may includea dedicated digital audio processor to perform those functions recitedor any other suitable functions. It should be appreciated from theforegoing that a microphone (not shown in FIG. 15) may be associatedwith the audio recorder 1612 to provide the audio input to the audiorecorder.

According to one embodiment, for example in which a technician maydictate notes, the audio processing of the audio input may includeperforming speech recognition (e.g., speech to text generation). Suchfunctionality may be provided by suitable speech recognition softwareexecuting on a dedicated audio processor, or in any other suitablemanner. Any generated text may be, for example, displayed on a displayof the user interface 126, or may be stored for later display on aseparate device.

The recordings provided by the audio recorder 1612 may be stored in adedicated audio memory, in local memory 122 and/or transmitted to anexternal device, such as the remote computer 150. In those embodimentsin which the audio recorder is a digital audio recorder, the audio filesmay be in any standard or proprietary audio file format (e.g., WAV, MP3,etc.).

Although not illustrated in FIG. 16, the communication interface 124 ofFIG. 15 may also serve as or enable another environmental sensor.According to one embodiment, the locate receiver may be internet enabledand information may be received via the communication interface 124 overthe internet. According to one embodiment, information about anenvironmental condition may be received via the communication interface.For example, temperature information or humidity information, amongothers, may be received over the internet via communication interface124. In such instances, the received temperature or humidity informationmay augment any temperature and humidity information collected by atemperature and humidity sensor of the locate receiver, or may replacesuch information, such that in some embodiments the locate receiver maynot include a physical temperature or humidity sensor. Thus, it shouldbe appreciated that the communication interface may serve as a “virtualsensor” by receiving environmental information of interest, not beinglimited to temperature and humidity.

It should be appreciated from the foregoing, as well as the furtherdiscussion below, that environmental information may be collected forvarious purposes. According to one embodiment, the environmentalinformation may be useful for assessing a locate device (e.g., locatereceiver) or locate operation. According to another embodiment, theenvironmental information may be useful for assessing the conditions inwhich marking material is being dispensed. As previously explained,locate operations may involve the use of a locate receiver to detect afacility location and a marking device to mark the facility location,for example by dispensing a marking material. The environmentalinformation sensed by the environmental sensors 1520 may be useful forassessing the conditions in which marking material is being dispensed inthose situations in which a marking device is being used in connectionwith the locate receiver. Some marking materials (e.g., paint), forexample, may have preferred temperature ranges and humidity levels,among other conditions, in which they may be dispensed. Thus,environmental information may facilitate determination of whether amarking material was or is being dispensed in suitable environmentalconditions.

As explained above, another type of input device which may be includedwith a locate receiver (or locate transmitter) is an operational sensor.Thus, according to one aspect of the present invention and as shown inFIG. 15, the locate receiver 1510 may include one or more operationalsensors 1530 for sensing one or more operating conditions orcharacteristics of the locate receiver.

FIG. 17 is a block diagram showing details of the operational sensorsshown in FIG. 15, according to one embodiment of the present invention.The illustrated exemplary operational sensors 1530 include, but are notlimited to, one or more temperature sensors 1702, a compass 1704, aninclinometer 1706, one or more accelerometers 1708, a yaw rate sensor1710, a proximity sensor 1712, a pressure sensor 1714, one or moredevice health sensors 1716, the image capture device 1610, and the audiorecorder 1612. Additional or alternative operational sensors may beincluded, and one or more of the illustrated operational sensors may beomitted, in some embodiments. The operational sensors may be coupled tothe processor 118 to receive control signals from the processor 118and/or to provide their respective outputs to the processor 118, and, asdescribed further below, may operate in one of various suitable manners.Information provided by any of the operational sensors may be stored inlocal memory 122, for example in an electronic record 1802, describedbelow, and/or transmitted to an external device, such as the remotecomputer 150, remote storage, etc.

One or more operational temperature sensors 1702 may be configured tosense any temperature of interest with respect to the locate receiver1510. For example, it may be desirable in some embodiments to monitorthe temperature of the processing circuitry of the locate receiver 1510,such as the temperature of the processor 118. Alternatively, it may bedesirable in some embodiments to monitor the temperature of othercomponents of the locate receiver 1510, for example, the temperature ofone of the other operational sensors 1530. Thus, it should beappreciated that a plurality of operational temperature sensors 1702 maybe included and arranged to sense any operating temperatures of interestof the locate receiver 1510. In this manner, the operating temperaturesof one or more components of the locate receiver 1510 may be monitoredand an alert or notification may be generated (e.g., by the controlelectronics) and provided to the technician if one of the operatingtemperatures is determined to be outside of an acceptable tolerance, forexample if a component is overheating. Alternatively, the temperaturefrom one or more operational temperature sensors 1702 may be used tocalibrate or compensate data or signals provided by any one of the othersensors which may have a temperature-dependent output.

The temperature sensor(s) 1702 may be any suitable temperature sensor,such as a temperature-dependent variable resistor, or any other type oftemperature sensor suitable for measuring the temperature of thecomponents of interest of the locate receiver. The temperature sensor1702 may be configured to operate over any suitable temperature range ofinterest, which in one embodiment may be from −40° F. to 125° F.,although other temperature ranges may be employed in other embodiments.The data output by the temperature sensor 1702 may be stored in localmemory 122 and/or may be transmitted to an external device, such asremote computer 150, in those embodiments in which the locate receiver1510 is communicatively coupled to the external device.

The compass 1704 may be configured to determine the direction in whichthe locate receiver 1510 is facing, and therefore may be positioned atone of various suitable locations. For example, according to oneembodiment, the compass 1704 may be positioned toward the top of thelocate receiver 1510, and aligned such that the compass identifies thedirection toward which the front of the locate receiver points (i.e.,the direction in which the locate receiver faces when held by thetechnician). The heading information provided by the compass 1704 may beprovided in degrees or in any other suitable units, and may be providedrelative to a reference direction (e.g., relative to true North).According to one embodiment, the compass may be initially calibrated totrue North, such that subsequent heading readings may be relative totrue North.

The heading information provided by the compass 1704 may be useful todetermine a direction in which the technician moves during a locateoperation. Such information may be particularly useful in instances inwhich the location tracking system 130 does not provide a signal or asufficiently accurate signal to monitor the technician's movements. Thecompass 1704 may be any suitable type of compass, including analog ordigital, and may provide any suitable readout. According to oneembodiment, the compass 1704 is a digital compass, which provides aheading of the locate receiver 1510. According to one embodiment, thecompass may include one or more gyroscopes. According to one embodiment,the compass 1704 is an OS4000-T solid state tilt compensated nanocompass available from OceanServer Technology, Inc. of Fall River, Mass.The information provided by the compass 1704 may be stored in localmemory 122 and/or transmitted to an external device, such as the remotecomputer 150.

The inclinometer 1706 may be any suitable inclinometer configurable tomeasure an angle of inclination of the locate receiver 1510. Accordingto one embodiment, the inclinometer may provide an angle with respect toground. According to one embodiment, the inclinometer may be amulti-axis digital device and may sense angles with respect tohorizontal and/or vertical planes. The inclinometer may provide avoltage as an output signal, indicative of the angle of inclination.According to some embodiments, the inclinometer may have an output rangespanning +/−30 degrees (e.g., with respect to ground), although otherranges may alternatively be provided by some inclinometers.

The inclinometer 1706 may be positioned toward the top of the locatereceiver 1510, for example, near where the technician may hold thelocate receiver during use. Alternatively, according to anotherembodiment, the inclinometer may be positioned substantially near thetip of the locate receiver 1510 (i.e., the end of the locate receiverheld proximate the ground when the locate receiver is in use) which maybe substantially the same as the tip 148 of locate receiver 110 shown inFIG. 5. Other locations for the inclinometer with respect to the locatereceiver are also possible.

The information provided by the inclinometer may be useful for one ormore of various purposes. For example, according to one embodiment, theinformation about the angle of the locate receiver may be useful indetermining whether the technician is appropriately using the locatereceiver (e.g., for determining whether the locate receiver is beingheld at a suitable angle relative to the surface (e.g., the ground)under which a facility is disposed), and in some instances may thereforebe used to disable part of the locate receiver (e.g., detectionelectronics 131) if the technician is holding the locate receiver at aninappropriate angle. According to another embodiment, as described infurther detail below in connection with FIG. 22, the information aboutthe angle of the locate receiver may be used to determine the locationof one point of the locate receiver relative to a second point of thelocate receiver (e.g., for use in determining the relative positioningof the tip of the locate receiver compared to the top of the locatereceiver). The information provided by the inclinometer may be stored inlocal memory 122 and/or transmitted to an external device, such as theremote computer 150.

One or more accelerometers 1708 may be configured to sense theacceleration of the locate receiver 1510 and may provide an output interms of g-force or in any other suitable units. Such information may beuseful, for example, in assessing whether a technician is appropriatelyusing (e.g., physically moving or manipulating) the locate receiver1510. For example, there may be predetermined acceptable accelerationranges associated with normal operation of the locate receiver (e.g.,associated with the typical sweeping motion of the locate receiver asthe technician scans for a buried facility), and therefore theaccelerometer(s) 1708 may provide information which may be used toassess whether a technician is operating the locate receiver 1510 withinthose acceptable ranges. In addition, any acceleration data provided bythe accelerometer(s) may be integrated to obtain velocity data and/orintegrated twice to obtain data about distance traveled (e.g., viaappropriate functionality included in the locate data algorithm 137 orother algorithm executed by the processor 118), either of whichintegration results may be useful for a variety of reasons. Theacceleration information provided by the accelerometer(s) 1708 may bestored in local memory 122 and/or transmitted to an external device,such as the remote computer 150.

The accelerometer(s) 1708 may be any suitable accelerometer for sensingthe acceleration of the locate receiver and may provide any suitableoutputs. According to one embodiment, the accelerometer may be a 3-axisaccelerometer, providing an indication of the acceleration of the locatereceiver along three orthogonal axes. The output of each axis may be afrequency (e.g., in Hz) or may be converted to units of g. For example,in one embodiment the accelerometer may be a 3-axis accelerometer thatoutputs a signal ranging from 0.5 Hz-550 Hz for the z-axis, from 0.5Hz-1600 Hz for the x-axis, and from 0.5 Hz-1600 Hz for the y-axis.Again, the accelerometer may alternatively provide an output in terms ofg or any other suitable units. In one exemplary implementation, anaccelerometer may be an ADXL 330KCPZ-RL accelerometer available fromAnalog Devices of Norwood, Mass. In some exemplary implementations, theaccelerometer may output acceleration data, whereas in otherimplementations the accelerometer may output velocity data along each ofthe three axes, as well as the orientation of the accelerometer.

In addition to providing acceleration data, an accelerometer may beoperated as an inclinometer according to known techniques (see, e.g.,description athttp://www.tilt-china.com/uploadPDF/How_to_use_an_accelerometer_as_an_inclinometer_pdf,viewed on Jan. 27, 2010 and prepared by Shanghai Vigor TechnologyDevelopment Co.). Thus, according to one embodiment of the presentinvention, a locate receiver may include an accelerometer configured tofunction as an inclinometer and therefore provide a measure ofinclination of the locate receiver.

Furthermore, as explained in greater detail below, the locate receiver1510 may comprise a plurality of accelerometers located at differentpositions with respect to the locate receiver. Information from suchaccelerometers may be useful, for example, in assessing the relativemotion of one portion (e.g., the tip) of the locate receiver withrespect to a second portion (e.g., the top) of the locate receiver, forexample using the techniques described in U.S. Patent ApplicationPublication 2008-0255795-A1, published Oct. 16, 2008, which is herebyincorporated herein by reference in its entirety. According to one suchnon-limiting embodiment, one accelerometer may be positioned near thetip of the locate receiver and a second accelerometer may be positionednear the top of the locate receiver. Both may be 3-axis accelerometers.Such an arrangement may also be used to determine the location of thetip of the locate receiver relative to the location of the top of thelocate receiver, as explained below in connection with FIG. 22.

Additionally, the data output by one or both accelerometers may be usedto monitor for out-of-tolerance operation of the locate receiver, suchas improper manipulation of the locate receiver by the technician. Forexample, acceleration data from either accelerometer may be indicativeof whether the locate receiver is being swung, thrown, or dropped, amongother things. For example, acceleration values from either accelerometerabove some threshold value for a sufficient duration (e.g., for onesecond or greater, or any other suitable duration) may be indicative ofthe locate receiver being thrown or dropped. The threshold value ofacceleration indicative of such behavior may be different for the twoaccelerometers. Similarly, detection of acceleration values deviatingfrom an expected or target pattern may be indicative of misuse of thelocate receiver. In response to detecting such manipulation of thelocate receiver, various actions may be taken, such as generating analert, logging an event, disabling the actuation system and/or detectionelectronics 131 of the locate receiver, or any of the actions describedfurther below.

Moreover, a locate receiver may be provided with two accelerometers tomonitor whether the locate receiver is being held in a satisfactorymanner during use. For example, it may be preferable for a locatereceiver to be maintained at a substantially perpendicular anglerelative to ground as a technician is locating, even when the technicianis moving (e.g., sweeping or swinging) the locate receiver. It should beappreciated that when operated in such a manner, the top of the locatereceiver and the tip of the locate receiver may exhibit similaracceleration characteristics (e.g., peaks in acceleration at the sametime (e.g., at the same points of a swinging motion), minimum values ofacceleration at the same time (e.g., at the same points of a swingingmotion), etc.) By positioning an accelerometer toward the tip of thelocate receiver and another toward the top of the locate receiver, theresulting acceleration data may be indicative of whether the technicianis holding the locate receiver perpendicular to ground or otherwiseproperly manipulating the locate receiver.

Other uses for multiple accelerometers on a locate receiver are alsopossible, and those examples listed above are non-limiting.

The operational sensors 1530 may further comprise a yaw rate sensor1710, which may be configured to sense the yaw rate (i.e., a twistingmotion) of the locate receiver. The yaw rate sensor may be any suitableyaw rate sensor and may provide its output in any suitable units, forexample in degrees per second (degrees/sec). One non-limiting example ofa suitable yaw rate sensor is an ADXRS610BBGZ-RL gyro sensor from AnalogDevices of Norwood, Mass. According to another embodiment, a yaw ratemeasurement may be provided by some types of compasses, such that acombination compass and yaw rate sensor may be used. The yaw rate sensormay be positioned at any suitable location on the locate receiver todetect yaw rate. The information provided by the yaw rate sensor 1710may be stored locally and/or transmitted to an external device such asthe remote computer 150.

The proximity sensor 1712 may be configured to measure the distance fromany point of interest of the locate receiver 1510 to a point of interestin its surroundings. For example, in one embodiment, the proximitysensor 1712 may be positioned at the tip of the locate receiver, and maybe oriented to determine the distance between the tip of the locatereceiver and any surface (e.g., a target surface) of interest, such asthe ground, a landmark, a wall, etc. Alternatively, in one embodiment,the proximity sensor may be positioned toward the top of the locatereceiver and oriented to determine a distance between the top of thelocate receiver and the target surface (e.g., ground). Otherconfigurations are also possible.

Information about the distance from the locate receiver to anysurrounding surface may be useful for one of various reasons. Forexample, such information may be useful in assessing whether atechnician is properly operating the locate receiver. As a non-limitingexample, there may be predetermined acceptable distances between thelocate receiver and the surface under which a facility is located whenscanning for the facility. As an example, it may be preferable in someembodiments to hold the locate receiver between one and twelve inchesfrom the surface. The proximity sensor may be used to determine whetherthe technician is maintaining the locate receiver at an acceptabledistance from the surface. Alternatively, according to anotherembodiment, and as described in greater detail below, the distance of aportion of the locate receiver from the ground may be useful indetermining the distance between two points of the locate receiver.

The proximity sensor 1712 may be any suitable type of proximity sensor(e.g., any commercially available proximity sensor), including an analogor digital device. In one embodiment, proximity sensor 1712 may be aSharp GP2D120 short range IR distance sensor from Sharp ElectronicsCorporation (Mahwah, N.J.) and is able to take a substantiallycontinuous distance reading and return a corresponding analog voltagewith a range of about 1.6 inches to about 12 inches. Such a proximitysensor may be suitable, for example, when the sensor is used to sensethe distance from the tip of the locate receiver to the ground, sincesuch a distance may typically be less than about 12 inches. According toanother embodiment, the proximity sensor may be a sonar device. Othertypes of proximity sensors may also be suitably used. The informationprovided by the proximity sensor 1712 (e.g., a distance value, forexample, in centimeters, meters, or feet) may be stored locally and/ortransmitted to an external device such as the remote computer 150.

The pressure sensor 1714 may be configured to sense any pressure ofinterest with respect to the locate receiver. For example, according toone embodiment it may be desirable to detect the pressure applied to ahandle of the locate receiver (e.g., handle 138 in FIG. 5), for instanceto determine whether a technician is holding the locate receiver and, ifso, whether it is being held appropriately. Accordingly, a pressuresensor may be positioned in the handle of the locate receiver in onenon-limiting embodiment and configured to detect the pressure applied tothe handle. According to another embodiment, it may be desirable todetermine the pressure applied to an actuation system of the locatereceiver, for example if the actuation system is a trigger (e.g.,actuator 142 in FIG. 5). Accordingly, a pressure sensor may beconfigured to determine the pressure applied to the trigger or otheractuation mechanism in those embodiments in which the locate receiverincludes such a trigger or actuation mechanism. According to oneembodiment, the locate receiver may include multiple pressure sensors,for example one for determining the pressure applied to a handle of thelocate receiver and one for determining a pressure applied to anactuation system of the locate receiver. However, any number of pressuresensors may be included, and they may be configured to sense anypressure of interest with respect to the locate receiver.

The pressure sensor 1714 may be any suitable type of pressure sensor fordetecting the pressure of interest. The information provided by thepressure sensor 1714, which may be in any suitable units, may be storedlocally and/or transmitted to an external device such as the remotecomputer 150.

The locate receiver may further include device health monitoringcapability. Characteristics of the health of the locate receiver whichmay be the subject of monitoring include, but are not limited to,battery life, battery drain level, battery charging capacity, wirelesssignal strength (in those embodiments in which the locate receiver haswireless capabilities), network connectivity, operating temperature,available memory, and the status of any one or more input devices of thelocate receiver, such as an accelerometer, location tracking system(e.g., GPS receiver), image capture device, light sensor, etc. To thisend, the locate receiver may include hardware and/or software configuredto serve the health monitoring purpose.

According to one embodiment, the locate receiver may include a processor(e.g., processor 118) configured to run a device health software programor application to process the inputs from one or more operationalsensors, such as operational temperature sensor 1702, to assess whetherthose inputs indicate the locate receiver is operating appropriately.According to another embodiment, the locate receiver may includededicated device health hardware, such as device health sensor 1716,which may provide data that is processed by a device health softwareprogram (for example, executing on processor 118) to assess the healthof the locate receiver. Non-limiting examples of device health sensor1716 include a voltmeter and an ammeter, among others.

In one embodiment, data provided by the device health sensor 1716 mayindicate that a low battery condition is present during the locateoperation and, thus, it may be determined that the operations of thelocate receiver are not reliable. Other device conditions, such aswireless signal strength (e.g., in those embodiments in which the locatereceiver 1510 is wirelessly coupled to an external device, such asremote computer 150), available memory, temperature of one or morecomponents of the locate receiver, power connection of one or morecomponents of the locate receiver, or other conditions of the locatereceiver may be monitored by a device health sensor. Thus, it should beappreciated that a locate receiver according to the embodimentsdescribed herein may include any suitable number of device healthsensors for monitoring a desired number of device conditions.

According to one embodiment, a record or message may be created based onoperation of the device health sensor. For example, a record or messagemay be created including a device ID (e.g., of the locate receiver) andthe current state of certain device components, such as input devices(e.g., environmental and operational sensors). The record or message mayalso or alternatively include an identification of any resourceutilization that is nearing a specified threshold (e.g., memory nearingcapacity). Thus, it should be appreciated that various conditions may bemonitored under the rubric of monitoring the health of the locatereceiver, and various actions taken in response to such monitoring.

The operational sensors 1530 may further comprise the image capturedevice 1610. As previously mentioned, the image capture device 1610 maybe considered an operational sensor, for example, if and when configuredto capture an image relating to the operation of the locate receiver1510.

Furthermore, the operational sensors 1530 may comprise an audiorecorder, similar to or the same as audio recorder 1612, and thereforeshown as audio recorder 1612 in FIG. 17. For example, the locatereceiver may include multiple audio recorders, with one or moreoperating as an environmental sensor (e.g., recording acoustic inputfrom the environment) and one or more operating as operational sensors(e.g., recording acoustic input relating to operation of one or morecomponents of the locate receiver. According to one embodiment, amicrophone associated with the audio recorder is positioned to detectsound emitted by a component of interest of the locate receiver. Theaudio input may also be stored by the audio recorder and processed inany suitable manner.

As previously described, the audio recorder may be any suitable audiorecorder, including a digital audio recorder or analog audio recorder,for example of any of the types previously described. In one embodiment,the audio recorder may comprise a dedicated PIC processor. In thoseembodiments in which the locate receiver includes two or more audiorecorders (e.g., one operating an as environmental sensor and anotheroperating as an operational sensor), the audio recorders may share anysuitable combination of circuitry. For example, multiple audio recordersmay share a same digital signal processor (e.g., a dedicated audiosignal processor). A separate microphone may be associated with eachaudio recorder, or a microphone may be shared between two or more audiorecorders. Thus, it should be appreciated that the exact configurationand components of audio recorders according to the various embodimentsdescribed herein are not limiting.

The audio files produced by an audio recorder operating as anoperational sensor may be stored locally in dedicated audio memory, inlocal memory 122 and/or transmitted to an external device, such as theremote computer 150.

In any of the embodiments illustrated in FIG. 15, any one or more of theenvironmental sensors 1520 illustrated in FIG. 16 and/or operationalsensors 1530 illustrated in FIG. 17 may be operated in any suitablemanner, including continuously, periodically, and/or in response to anevent or trigger (e.g., one or more actuations of the locate receiver),or in any other suitable manner. For example, one or more of theenvironmental sensors 1520 and/or operational sensors 1530 may operatecontinuously during performance of a locate operation. In particular,the ambient temperature sensor may output a substantially continuousdata stream indicative of the sensed ambient temperature. Similarly, thesurface temperature sensor, humidity sensor, and light sensor may outputsubstantially continuous data streams indicative of the respectivesensed conditions. The inclinometer, compass, accelerometer, yaw ratesensor, proximity sensor, pressure sensor, and device health sensor mayalso output substantially continuous data streams indicative of thesensed operation. The image capture device 1610 may record a videosequence continuously during the locate operation, and the audiorecorder 1612 may continuously record any audio input during performanceof the locate operation.

Alternatively, one or more of the environmental sensors 1520 and/oroperational sensors 1530 may be operated and/or polled periodically,with the resulting output data being logged and/or transmittedperiodically. For example, the ambient temperature sensor may provide anoutput signal indicative of the sensed ambient temperature every second,every five seconds, every ten seconds, every minute, every ten minutes,or at any other suitable time interval. Similarly, the surfacetemperature sensor, humidity sensor, light sensor, operationaltemperature sensor(s), inclinometer, compass, accelerometer(s), yaw ratesensor, proximity sensor, pressure sensor, and device health sensor(s)may output data at periodic intervals. The image capture device maycapture a still image or a video sequence of any desired duration atperiodic intervals. The audio recorder may capture audio of any desiredduration at periodic intervals. It should be appreciated that in someembodiments one or more of the environmental sensors 1520 and/oroperational sensors 1530 may themselves operate so as to provide outputinformation in an essentially continuous fashion, but only be read orpolled (e.g., by processor 118) on some discrete or periodic basis.Accordingly, output signals or data provided by one or more sensors maybe acquired, logged into local memory, and/or transmitted to an externaldevice in any of a variety of manners.

According to another embodiment, one or more of the environmentalsensors 1520 and/or operational sensors 1530 may operate, be readdiscretely, and/or be polled, and therefore the corresponding data maybe logged and/or transmitted, in response to actuation of the actuationsystem 120 of the locate receiver. For example, actuation of theactuation system 120 may trigger collection of magnetic field data andsimultaneously may trigger recording of a sensed ambient temperaturefrom ambient temperature sensor 1602 in the local memory 122. Theremaining environmental sensors 1520 and/or operational sensors 1530 maybe operated, read and/or polled in a similar manner.

In one embodiment, one or more of the environmental sensors 1520 and/oroperational sensors 1530 may be activated, read discretely, and/orpolled by the technician irrespective of whether the actuation system120 is actuated. For example, the technician may activate, read, and/orpoll one or more of the environmental sensors by depressing a selectionbutton corresponding to the environmental sensor(s), by choosing aselection button or menu option from a user interface of the locatereceiver (in those embodiments in which the locate receiver includes auser interface), or in any other suitable manner. The operationalsensors may operate similarly.

Thus, it should be appreciated that the operation of sensors, andreading and/or logging and/or transmitting of data from theenvironmental sensors 1520 and operational sensors 1530, is not limitedto any particular manner or time, but rather that various suitableschemes are contemplated. Also, it should be appreciated that in thoseembodiments in which a locate receiver comprises multiple sensors, thesensors need not operate in the same manner as each other. For example,one or more of the sensors may operate periodically while one or moremay only provide their data output in response to actuation of thelocate receiver actuation system. In one embodiment, a plurality of thesensors may provide their data outputs periodically, but at differentrates. As an example, the accelerometers and yaw rate sensor of thelocate receiver may output their data at relatively high frequencies,such as in the kHz range, MHz range, or higher. The temperature sensors,humidity sensor, and light sensor may output their data at relativelylower frequencies, such as approximately 1 Hz, for example because thosequantities may not change as rapidly as the quantities measured by theaccelerometers and the yaw rate sensor. Other operating schemes are alsopossible.

According to one embodiment, the output data from the sensors is onlyread and stored upon actuation of the actuation system 120, even thoughthe sensors may update their outputs at the above-indicated frequenciesor any other suitable frequencies. Upon such actuation, data from anyone or more of the sensors may be read out and stored in memory. Thestored data may therefore represent the values present at the sensors atthe time of actuation. In this manner, data values output by the sensorswhen the trigger is not actuated may not be stored in some instances,but rather may be updated by the subsequent data value from the sensor.In this manner, only the most recent data from the sensors may be storedupon actuation. Other operating schemes are also possible.

As mentioned previously, environmental information and/or operationalinformation output by any one or more environmental sensors andoperational sensors of the locate receiver (e.g., of the environmentalsensors 1520 and/or operational sensors 1530) may be used for one ormore of various purposes, some of which have been previously described.Examples of such purposes include assessing whether a locate operationwas or is being performed within environmental and/or operationaltolerances, interacting with the technician and/or controlling/alteringoperation of the locate receiver, and augmenting data records/files.

To this end, the various environmental information and/or operationalinformation provided by various sensors may be organized and handled asdata in various formats, and in some implementations may be organized interms of events and corresponding event entries formatted according to aparticular protocol, for example as discussed above in connection withTables 2 through 5. Event entries similar to these and including variousenvironmental and/or operational information may be generated by thelocate receiver at some point once information has been read/acquiredfrom environmental and/or operational sensors, the event entriesthemselves (or any information contained therein) may be logged in afile for an electronic record, and/or the event entries themselves (orany information contained therein) may be transmitted by the locatereceiver (e.g., to remote computer 150).

In some implementations, environmental information and/or operationalinformation may be contained within one or more event entriescorresponding to an actuation of the locate receiver, such that theenvironmental information and/or the operational information is part ofan actuation data set. Table 12 below illustrates a modification of anevent entry originally depicted in Table 3 above, in which environmentalinformation and operational information is included as part of the dataformatted in an actuation event entry, according to one example. Theinformation for acceleration may include three values for each axis ofeach accelerometer. One value for a particular axis may be a raw value,the second value for a particular axis may be a high-pass filteredvalue, and the third value may be a low-pass filtered value. Data valuesare only shown for one of the two accelerometers listed. Locateinformation from one or more input devices/other components of thelocate receiver is recorded with these events to provide informationabout the job in progress.

TABLE 12 Format INFO+ LCTR: (DATE) (TIME) (GPS data) (FACILITY TYPE)(GROUND TYPE) (MAGNETIC FIELD STRENGTH AS % OF FULL SCALE info)(DETECTED SIGNAL FREQUENCY) (GAIN) (AMB TEMP info) (SURF TEMP info) (HUMinfo) (LIGHT info) (ALTITUDE info) (IMAGE info) (AUDIO info) (OP TEMPinfo) (COMPASS info) (INCL info) (ACC1 info) (ACC2 info) (YAW info)(PROX info) (DH1 info) (DH2 info) <CR><LF> Examples INFO+LCTR:DATE(2009-04-15) TIME(12:04:44) GPS($GPGGA, 120443, 4807.038, N,01131.000, E, 1, 08, 0.9, 545.4, M, 46.9, M,, *47) FACILITY TYPE(YELLOW) GROUND TYPE (PAVEMENT) STRENGTH(80) FREQUENCY(512) GAIN (10)AMB TEMP(73F) SURF TEMP(78F) HUM(32) LIGHT(1500) ALT(200) IMAGE(Y)AUDIO(Y) OP TEMP(97F) COMPASS(243) INCL(−20) ACC1_x_raw(.287)ACC1_x_high(.283) ACC1_x_low(.275) ACC1_y_raw(.385) ACC1_y_high(.382)ACC1_y_low(.381) ACC1_z_raw(.153) ACC1_z_high(.150) ACC1_z_low(.145)(ACC2(!) YAW(!) PROX(15) DH1(67) DH2(!) <CR><LF> INFO+LCTR:DATE(2009-04-15) TIME(12:04:45) GPS($GPGGA, 120445, 4807.038, N,01131.000, E, 1, 08, 0.9, 545.4, M, 46.9, M,, *47) FACILITY TYPE(YELLOW) GROUND TYPE (GRASS) STRENGTH(81) FREQUENCY (512) GAIN (10) AMBTEMP(73F) SURF TEMP(78F) HUM(31) LIGHT(1500) ALT(200) IMAGE(Y) AUDIO(Y)OP TEMP(97F) COMPASS(243) INCL(−20) ACC1_x_raw(.285) ACC1_x_high(.280)ACC1_x_low(.275) ACC1_y_raw(.385) ACC1_y_high(.385) ACC1_y_low(.380)ACC1_z_raw(.156) ACC1_z_high(.150) ACC1_z_low(.145) ACC2(!) YAW(!)PROX(14) DH1(67) DH2(!) <CR><LF> INFO+LCTR: DATE(2009-04-15)TIME(12:04:46) GPS($GPGGA, 120446, 4807.038, N, 01131.000, E, 1, 08,0.9, 545.4, M, 46.9, M,, *47) FACILITY TYPE (YELLOW) GROUND TYPE (DIRT)STRENGTH(80) FREQUENCY(512) GAIN (11) AMB TEMP(73F) SURF TEMP(78F)HUM(31) LIGHT(1500) ALT(200) IMAGE(Y) AUDIO(Y) OP TEMP(97F) COMPASS(243)INCL(−20) ACC1_x_raw(.285) ACC1_x_high(.380) ACC1_x_low(.275)ACC1_y_raw(.385) ACC1_y_high(.382) ACC1_y_low(.390) ACC1_z_raw(.155)ACC1_z_high(.150) ACC1_z_low(.147) ACC2(!) YAW(!) PROX(15) DH1(67)DH2(!) <CR><LF>

The contents of an information field for a particular piece ofenvironmental information and/or operational information in an evententry may have any of a number of forms; for example, the content may bestrictly numeric (e.g., according to some predetermined scale/units ofmeasure for the numeric information), alphanumeric (e.g., 78 F), text(e.g., YES), symbolic (e.g., Y or N to indicate “yes” or “no,” or someother symbol to provide an indication, such as ! to indicate sensorfailure or no sensor information available), or referential in nature(e.g., a filename, pointer or other link to provide an indication ofwhere relevant information relating to the particular environmentaland/or operational condition may be found).

In other implementations, one or both of environmental informationand/or operational information may be formatted in one or moreparticular event entries generated specifically to provide suchinformation, in a manner that is not necessarily related to actuation ofthe locate receiver. For example, such “sensor read events” may begenerated as the result of the processor reading one or moreenvironmental and/or operational sensors one or more times while a jobis in progress (e.g., on a periodic basis pursuant to processor polls).Table 13 below provides an example of such a sensor read event entry.

TABLE 13 Format INFO+SENSOR: (DATE) (TIME) (AMB TEMP info) (SURF TEMPinfo) (HUM info) (LIGHT info) (IMAGE info) (AUDIO info) (OP TEMP info)(COMPASS info) (INCL info) (ACC1 info) (ACC2 info) (YAW info) (PROXinfo) (PRESSURE info) (DH1 info) (DH2 info) <CR><LF> ExamplesINFO+SENSOR: DATE(2009-04-15) TIME(12:04:45) AMB TEMP(73F) SURFTEMP(78F) HUM(31) LIGHT(1500) IMAGE(Y) AUDIO(Y) OP TEMP(97F)COMPASS(243) INCL(−40) ACC1(.285) ACC2(!) YAW(!) PROX(15) PRESSURE (54)DH1(67) DH2(!)<CR><LF>

With respect to file formats for electronic records including evententries or information derived therefrom, as discussed above any numberof file formats may be employed (e.g., ASCII, XML).

FIG. 18 illustrates an electronic record 1802, similar to the electronicrecord 135 previously described in connection with FIGS. 7 and 9, whichmay be generated by a locate receiver 1510, stored in local memory 122of the locate receiver, and/or transmitted in whole or part by thelocate receiver, according to one embodiment. Some or all of theinformation provided in the electronic record 1802 may be derived froman event entry generated by the locate receiver (e.g., an event entry isgenerated and then parsed to provide information in various fields of anelectronic record), or the information contained in the electronicrecord 1802 may be provided in another manner pursuant to the conceptsdisclosed herein (e.g., sensor information may be acquired directly fromone or more sensors, and acquired information may be stored in theelectronic record without necessarily generating an event entry). Inaddition to the information elements shown previously in FIGS. 7 and 9,the electronic record 1802 may further include one or both ofenvironmental information 1804 and operational information 1806. Whileboth types of information are shown for simplicity in FIG. 18, it shouldbe appreciated that an electronic record according to variousembodiments need not include both environmental information andoperational information.

The exemplary electronic record 1802 shown in FIG. 18 may be used toevaluate performance of a locate operation, for example, by reviewinginformation in the actuation data set 702C, the ticket information 714,service-related information 716, the environmental information 1804and/or the operational information 1806. It should be appreciated thatthe electronic record 1802 includes some information that assumes thatthe locate receiver 1510 includes the timing system 128 and the locationtracking system 130, such as the timing and location information shownin the electronic record.

Table 14 provides an example of a data record that may be generated bylocate receiver 1510 upon actuation of the actuation system. Each shown“act” corresponds to a separate actuation. As shown, the data record mayinclude information about the service provider identification, the user(technician) identification, the locate receiver identification, thereceiver mode, a timestamp (for example, provided by a timing systemsuch as timing system 128), geo-location data, signal strength data,gain of the locate receiver, signal frequency data, facility depth data,facility type data, ground type data, locate request data, andinformation relating to the environmental sensors 1520. This example isprovided for purposes of illustration, and is not limiting, as manydifferent forms of data records may be generated based on the operationof the locate receiver 1510.

TABLE 14 Example record of data acquired by locate receiver 1510 uponactuation Record Service provider ID 0482 # act-1 User ID 4815 ReceiverID 7362 Receiver Mode Mode = Peak Receiver Mode ACTIVE Timestamp data12-Jul-2008; 09:35:15.2 Geo-location data 2650.9348, N, 08003.5057, WSignal strength (% of 85 maximum) Gain 45 Signal frequency (kHz) 1Facility depth (meters) 3.4 Facility type Gas (yellow) Ground typePavement Locate request data Requestor: XYZ Construction Company,Requested service address: 222 Main St, Orlando, FL Ambient temperature75 (° F.) Surface temperature 80 (° F.) Humidity (%) 85 Illuminance(lux) 15000 Altitude (meters) 200 Image captured (Y/N) Y Audio captured(Y/N) N Record Service provider ID 0482 # act-2 User ID 4815 Receiver ID7362 Receiver Mode Mode = Peak Receiver Mode ACTIVE Timestamp data12-Jul-2008; 09:35:17.5 Geo-location data 2650.9448, N, 08203.5057, WSignal strength (% of 83 maximum) Gain 45 Signal frequency (kHz) 1Facility depth (meters) 3.3 Facility type Gas (yellow) Ground typePavement Locate request data Requestor: XYZ Construction Company,Requested service address: 222 Main St, Orlando, FL Ambient temperature75 (° F.) Surface temperature 80 (° F.) Humidity (%) 84 Illuminance(lux) 15500 Altitude (meters) 200 Image captured (Y/N) Y Audio captured(Y/N) N Record Service provider ID 0482 # act-3 User ID 4815 Receiver ID7362 Receiver Mode Mode = Peak Receiver Mode ACTIVE Timestamp data12-Jul-2008; 09:35:18.7 Geo-location data 2650.9358, N, 08003.5067, WSignal strength (% of 86 maximum) Gain 45 Signal frequency (kHz) 1Facility depth (meters) 3.4 Facility type Gas (yellow) Ground typePavement Locate request data Requestor: XYZ Construction Company,Requested service address: 222 Main St, Orlando, FL Ambient temperature74 (° F.) Surface temperature 81 (° F.) Humidity (%) 85 Illuminance(lux) 15200 Altitude (meters) 200 Image captured (Y/N) Y Audio captured(Y/N) N

In a manner similar to Table 14, Table 15A provides another example of adata record that may be generated by locate receiver 1510 upon actuationof the actuation system. Each shown “act” corresponds to a separateactuation. As shown, the data record may include information about theservice provider identification, the user (technician) identification,the locate receiver identification, the receiver mode, a timestamp (forexample, provided by a timing system such as timing system 128),geo-location data, signal strength data, gain of the locate receiver,signal frequency data, facility depth data, facility type data, groundtype data, locate request data, and information relating to theoperational sensors 1530. The location tracking system 130 provides thegeo-location data. The temperature sensor(s) 1702 provides thetemperature data. The compass 1704 provides the heading. Theinclinometer 1706 provides the inclination. The accelerometer(s) 1708provides the acceleration, and in this embodiment is a 3-axisaccelerometer. The yaw rate sensor 1710 provides the yaw rate. Theproximity sensor 1712 provides the distance, which may represent thedistance from the tip of the locate receiver to the ground, in onenon-limiting embodiment. The pressure sensor 1714 provides the pressuremeasurement. This example is provided for purposes of illustration, andis not limiting, as many different forms of data records may begenerated based on the operation of the locate receiver 1510.

TABLE 15A Example record of data acquired by locate receiver 1510 uponactuation Record Service provider ID 0482 # act-1 User ID 4815 ReceiverID 7362 Receiver Mode Mode = Peak Receiver Mode ACTIVE Timestamp data12-Jul-2008; 09:35:15.2 Geo-location data 2650.9256, N, 08003.5234, WSignal strength (% of 86 maximum) Gain 45 Signal frequency (kHz) 1Facility depth (meters) 3.4 Facility type Gas (yellow) Ground typePavement Locate request data Requestor: XYZ Construction Company,Requested service address: 222 Main St, Orlando, FL Temperature (° F.)75 Heading (degrees) 243 Inclination (degrees) 25 Acceleration (g)(x-axis) 0.75 Acceleration (g) (y-axis) 1.20 Acceleration (g) (z-axis)0.90 Yaw rate (degrees/sec) 10 Distance (cm) 15 Pressure (pounds/in²) 45Image captured (Y/N) Y Audio captured (Y/N) N Record Service provider ID0482 # act-2 User ID 4815 Receiver ID 7362 Receiver Mode Mode = PeakReceiver Mode ACTIVE Timestamp data 12-Jul-2008; 09:35:17.5 Geo-locationdata 2650.9256, N, 09003.5234, W Signal strength (% of 86 maximum) Gain45 Signal frequency (kHz) 1 Facility depth (meters) 3.4 Facility typeGas (yellow) Ground type Pavement Locate request data Requestor: XYZConstruction Company, Requested service address: 222 Main St, Orlando,FL Temperature (° F.) 75 Heading (degrees) 243 Inclination (degrees) 25Acceleration (g) (x-axis) 0.80 Acceleration (g) (y-axis) 1.50Acceleration (g) (z-axis) 0.70 Yaw rate (degrees/sec) 9 Distance (cm) 14Pressure (pounds/in²) 48 Image captured (Y/N) Y Audio captured (Y/N) NRecord Service provider ID 0482 # act-3 User ID 4815 Receiver ID 7362Receiver Mode Mode = Peak Receiver Mode ACTIVE Timestamp data12-Jul-2008; 09:35:18.7 Geo-location data 2650.9256, N, 08003.5234, WSignal strength (% of 86 maximum) Gain 45 Signal frequency (kHz) 1Facility depth (meters) 3.5 Facility type Gas (yellow) Ground typePavement Locate request data Requestor: XYZ Construction Company,Requested service address: 222 Main St, Orlando, FL Temperature (° F.)75 Heading (degrees) 245 Inclination (degrees) 27 Acceleration (g)(x-axis) 0.50 Acceleration (g) (y-axis) 1.00 Acceleration (g) (z-axis)1.00 Yaw rate (degrees/sec) 11 Distance (cm) 14 Pressure (pounds/in²) 50Image captured (Y/N) Y Audio captured (Y/N) N

While Tables 14 and 15A respectively indicate the collection ofenvironmental information and operational information separately, and aspart of an actuation data set, it should be appreciated that variousembodiments of the present invention are not limited in this respect. Inparticular, both environmental information and operational informationmay be collected together as part of a given actuation data set.Furthermore, the inclusion of one or both of environmental informationand operational information in an electronic record such as theelectronic record 1802 need not be limited to one or more particularactuation data sets; rather, in some exemplary implementations, one orboth of environmental information and operational information may beincluded as a unique component of an electronic record apart from anyparticular actuation data set (e.g., one or both of environmental andoperational information may be common to, or “shared by,” one or moreactuation data sets).

As mentioned previously, locate transmitters may also includeenvironmental and/or operational sensors to sense environmental and/oroperating conditions. Such information may be useful in assessing thegeneral environmental conditions of a locate operation and the operatingconditions of the locate transmitter, among other things. FIG. 26illustrates a non-limiting example of a locate transmitter includingenvironmental and operational sensors.

As shown, the data acquisition system 2600 includes a locate transmitter2610 and the remote computer 150. The locate transmitter 2610 includescontrol electronics 2612, including a processor 2618, local memory 2622,a communication interface 2624, a user interface 2626, a timing system2628, and a location tracking system 2630. Those components may besubstantially the same as the previously described components of controlelectronics 112, and therefore are not described in detail now. Thecontrol electronics also includes an activation system 2620, which mayprovide a technician with the capability to generate an applied signalusing the locate transmitter 2610. The activation system may comprise amechanical and/or electrical mechanism. For example, the activationsystem 2620 may be a switch, button, knob, dial, or other activationdevice, and may provide the capability for setting the frequency andamplitude of the applied signal 2632. Furthermore, the activation system2620 may be used to prompt the capture and/or storage of certain locateinformation generated and/or received by locate transmitter (e.g.,applied signal frequency, applied signal amplitude, status of the locatetransmitter, environmental and/or operational information, or any othertypes of locate information described herein), in a manner similar tothat described above in connection with the actuation systems of thedescribed locate receivers. Alternatively, the locate information may becollected and/or stored according to any of the previously describedschemes for locate receivers (e.g., continuously, periodically, inresponse to an event, etc.).

In response to activating the activation system, the transmittercircuitry 2631 may generate and transmit the applied signal 2632. Thetransmitter circuitry 2631 may be any transmitter circuitry capable ofgenerating a suitable applied signal. According to one embodiment, thetransmitter circuitry 2631 is configured to provide an applied signal ofvariable frequency and amplitude. For example, the frequency of appliedsignal 2632 may be adjustable in increments from about 50 Hz to about200 kHz, as a non-limiting example.

As shown, the locate transmitter 2610 also includes a power source 2614,which may be substantially the same as previously described power source114, and which is therefore not described in detail now.

Moreover, the locate transmitter includes the environmental sensors1520, operational sensors 1530, and light source 1532. These componentsmay be positioned at any suitable location(s) of the locate transmitter,and may operate as previously described.

Information collected by the locate transmitter 2610 may be used to forman event entry and/or an electronic record. For example, event entriessimilar to those shown in Tables 12 and 13 may be generated in thecontext of the locate transmitter 2610. Similarly, an electronic recordsimilar those of Tables 14 and 15A may be generated. As a non-limitingexample, Table 15B illustrates an electronic record which may begenerated by the locate transmitter 2610, for example in response toactivation of the activation system 2620.

TABLE 15B Example record of data acquired by locate transmitter 2610upon activation Record Service provider ID 0482 # act-1 User ID 4815Transmitter ID 7362 Transmitter Mode Inductive Timestamp data12-Jul-2008; 09:35:15.2 Geo-location data 2650.9256, N, 08003.5234, WApplied signal 115 amplitude (Volts) Applied signal 60 frequency (Hz)Facility type Gas (yellow) Ground type Pavement Locate request dataRequestor: XYZ Construction Company, Requested service address: 222 MainSt, Orlando, FL Temperature (° F.) 75 Humidity (%) 31 Illuminance (lux)15200 Altitude (meters) 210 Acceleration (g) (x-axis) 0.05 Acceleration(g) (y-axis) 0.05 Acceleration (g) (z-axis) 0.00 Yaw rate (degrees/sec)10 Image captured (Y/N) Y Audio captured (Y/N) N

It should be appreciated that Table 15B illustrates a non-limitingexample of an electronic record that may be generated in accordance withoperation of the locate transmitter 2610, and that other forms ofelectronic records including other types of information may also oralternatively be generated.

In addition, it should be appreciated that in some embodiments a locatetransmitter and locate receiver may communicate with each other and/or aremote computer, such as remote computer 150. For example, in oneembodiment each of a locate transmitter and locate receiver forming alocate set may communicate directly with a remote computer, for exampleto provide the types of information identified in Tables 14, 15A, and15B. According to another embodiment, one of the locate receiver andlocate transmitter may send its information (e.g., the informationillustrated in Tables 14, 15A, and 15B) to the other of the two. Thedevice receiving such information may then send the information to theremote computer (or other type of remote device). Other schemes forcommunication between a locate receiver and locate transmitter are alsopossible.

VII. Assessing Operation and/or Use of a Locate Device

Environmental information and/or operational information, as well as anyof the other constituent components of locate information and landmarkinformation discussed herein, may be used to assess whether a locatedevice (e.g., locate receiver) is being used and/or a locate operationwas or is being performed in accordance with recommended practices orwithin recommended environmental or operational conditions. Forsimplicity, the following discussion focuses on locate receivers,although the concepts described also apply to locate transmitters, suchas previously described locate transmitter 2610.

As an illustrative example, there may be certain preferred environmentalconditions in which a locate receiver may be used and/or a locateoperation may be performed.

Additionally, there may be certain preferred process tolerances withrespect to performing locate operations. For example, there may be aminimum ambient light specification, a certain angle specification withrespect to the locate receiver relative to a target surface, a certaindistance specification (i.e., distance from target surface), a certainmotion specification with respect to sweeping the locate receiver, andthe like. Violations of these process tolerances may result in poorlyperformed locate operations, which may result in poor customersatisfaction and an increased risk of damage to facilities.

Other environmental and operational tolerances may also be applicable tolocate operations, and it should be appreciated that those listed aboveare non-limiting examples provided for purposes of illustration.

In view of the foregoing, according to another aspect of the presentinvention, a locate receiver, or a locate operations system comprising alocate receiver, may include an operations monitoring application thatoperates in combination with the locate receiver or that is installedfully or in part on the locate receiver. In exemplary implementationsdiscussed below, an operations monitoring application may provide fordetecting and monitoring the use of locating equipment such as thelocate receivers described herein for out-of-tolerance environmental oroperational conditions. For example, the operations monitoringapplication of the present disclosure may provide for detecting andmonitoring the use of the locate receiver within the limits of itsproduct specifications with respect to, for example, the ambienttemperature and humidity. Additionally or alternatively, monitoring maybe based on certain standard operating procedures (e.g., as establishedby a facility owner, a locate contractor, a regulatory body, etc.).Other bases for monitoring the operation of a locate receiver may alsobe used.

According to one aspect of this embodiment, once an out-of-tolerancecondition is detected, either environmental or operational, anout-of-tolerance alert or notification may be provided to the user(technician) of the locate receiver. In some exemplary implementations,the out-of-tolerance alert may be generated by the control electronicsof the locate receiver, although not all implementations are limited inthis respect. Additionally or alternatively, a record of suchout-of-tolerance alerts may be stored, such as a record of alertacknowledgments that may be stored or transmitted by the locate receiverin response to technician acknowledgement of the alert.

An example of an operations monitoring application is now described. Forpurposes of illustration, the operations monitoring application isdescribed in connection with locate receiver 1510 discussed above inconnection with FIG. 15. However, it should be appreciated that theoperations monitoring application may be used in connection with otherlocate receivers described herein, as well as with locate transmitters(e.g., locate transmitters equipped with environmental and/oroperational sensors).

Referring to FIG. 19, a functional block diagram of an example of anoperations monitoring application 1900 for detecting and monitoring theuse of a locate receiver (e.g., locate receiver 1510 in thisnon-limiting example) for out-of-tolerance conditions is presented.Operations monitoring application 1900 may include an operationsalgorithm 1906, which is a software algorithm for determining whetherout-of-tolerance environmental and/or operational conditions are presentduring locate operations and/or whether violations of certain processtolerances occur.

To make determinations of out-of-tolerance conditions/occurrences,operations algorithm 1906 may compare information supplied at anexpected data input 1910 to information supplied at an actual data input1914. For example, an operating limits table 1904 may provide the sourceof information feeding expected data input 1910. An example of thecontents of operating limits table 1904 is shown in Table 16 below. Itshould be appreciated that such a table may include entries for any oneor more conditions sensed by a sensor of the locate receiver, and thatthose entries shown are non-limiting examples. Also, operating limitstable 1904 may include information applicable to locate transmitters inthose embodiments in which a locate transmitter is being used.

TABLE 16 Example contents of operating limits table 1904 Quantity ValueMaximum ambient temperature 100 degrees F. Minimum ambient temperature 0degrees F. Maximum surface temperature 150 degrees F. Minimum surfacetemperature 40 degrees F. Maximum ambient humidity 90% Minimum ambientlight level 2.0 volts Maximum altitude 2000 meters Minimum angle −30degrees Maximum angle 30 degrees Minimum locate distance 1 inch Maximumlocate distance 10 inches Maximum motion rate (e.g., sweeping rate) 1.5g Maximum yaw rate 30 degrees/second Maximum pressure 150 psi Minimumbattery strength 15% Difference between actual vs. expected geo- 0.2miles from location location on ticket Locate receiver frequency =locatetransmitter frequency Minimum received signal strength 50%

The contents of operating limits table 1904 may be informed by standardoperating procedures (SOP) information 1902. In this respect, thecontents of operating limits table 1904 may have a dynamic component.That is, in the event that the content of SOP information 1902 ismodified and/or that the content of SOP information 1902 varies, forexample from one geographic location to another or from one job/worksite to another, the content of operating limits table 1904 mayautomatically vary accordingly. SOP information 1902 may includeinformation, such as, but not limited to, state, local, and/or regionalregulations with respect to underground facility locate and markingoperations; locate service provider policy information; contractualinformation; and the like. Further, SOP information 1902 may includeinformation about the current industry-accepted best practices and/orprocedures with respect to underground facility locate and markingoperations.

One source of information that may be included in SOP information 1902may be, for example, the information of the Best Practices Version 6.0document, published in February 2009 by the Common Ground Alliance (CGA)of Alexandria, Va. (www.commongroundalliance.com), which document ishereby incorporated herein by reference in its entirety (this documentis a compilation of current recommended practices designed to preventdamage to underground facilities). Other sources of information for SOPinformation 1902 are also possible.

Generally, the contents of operating limits table 1904 may be variableand dynamic based on one or more factors, such as, but not limited to,dynamic information that may be included in SOP information 1902, bestpractices that may vary with time of year, best practices that may varywith time of day, best practices that may vary with weather conditions,best practices that may vary with the skill level of the locatetechnician, and the like.

According to one embodiment, the information supplied to actual datainput 1914 is generated and/or collected in real time during locateoperations that are performed in the field. For example, the source ofinformation feeding actual data input 1914 may be the locate receiver1510, although locate receiver 1510 is only a non-limiting example, asany of the locate receivers described herein may be used. The actualdata input 1914 may be fed with the data from one or more of the sensors1520 and 1530, which data is indicated generally in FIG. 19 as sensordata 1916.

Referring again to Table 16, the values that are contained in operatinglimits table 1904 may be expressed in terms that correspond to the dataformat that is returned from sensors 1520 and 1530. For example, in oneembodiment the light sensor 1608 output may be a voltage, and thus theambient light level may be expressed in volts in operating limits table1904. However, the values in table 1904 are not limited to being in anyparticular format.

Operations algorithm 1906 may compare the information of operatinglimits table 1904 that is present at expected data input 1910 to theinformation of sensor data 1916 that is present at actual data input1914 to determine whether out-of-tolerance environmental and/oroperational conditions and/or violations of certain process tolerancesare present during locate operations. In one example, operationsalgorithm 1906 may determine whether locate operations are beingperformed when the ambient temperature is too hot or too cold, or whenthe ambient humidity is too high. In another example, operationsalgorithm 1906 may determine whether the locate receiver angle ordistance detected during locate operations exceed acceptable parameters.In yet another example, operations algorithm 1906 may determine whetherlocate operations are being performed when it is too dark, based on acomparison of a sensed light level to a light level specification.

When out-of-tolerance environmental and/or operational conditions and/orviolations of certain process specifications are detected, operationsalgorithm 1906 may generate out-of-tolerance alerts 1912, the contentsof which may reflect the nature of the out-of-tolerance condition. Thealerts may take any suitable form, such as an audible alert (a chime, aring tone, a verbal message or command (e.g., synthesized speechprovided by a text-to-speech synthesizer of the locate receiver), etc.,for example presented via a speaker of the locate receiver), a visualalert (e.g., a text display presented via display 146 or any othersuitable display, an indicator light, etc.), a tactile alert (e.g.,vibration of a tactile indicator, as described below in connection withFIG. 24), any combination of those options, or any other suitable typeof notification.

Any out-of-tolerance alerts 1912 that are generated may be logged in analerts log 1908 of operations monitoring application 1900. Further, inthose embodiments in which the operations monitoring application 1900 isnot loaded and running on the locate receiver itself, anyout-of-tolerance alerts 1912 that are generated may be transmitted tothe locate receiver 1510, in which the control electronics 112 mayprocess the out-of-tolerance alerts 1912. For example, controlelectronics 112 may receive out-of-tolerance alerts 1912 and present thecontents thereof to the user of locate receiver 1510 (e.g., visuallyand/or audibly via the display 146 and/or a speaker, via a tactileindicator, etc.).

Additionally, control electronics 112 may generate alert acknowledgments1918 that correspond to out-of-tolerance alerts 1912. Alertacknowledgments 1918 may be returned to operations monitoringapplication 1900 and logged in alerts log 1908. Alert acknowledgments1918 provide evidence that out-of-tolerance alerts 1912 have beenreceived and processed at locate receiver 1510. The contents of alertslog 1908 may be useful to various business applications with respect tolocate operations. For example, the contents of alerts log 1908 may beuseful to business applications for assessing the quality of locateoperations that are performed in the field, assessing the skill and/orcompetency levels of technicians, and the like. In a specific example,out-of-tolerance alerts 1912 in alerts log 1908 may be monitored in realtime by, for example, management personnel of locate companies (e.g.,locate contractors, facility owners) regulatory authorities, or otheragencies, wherein certain actions in response to out-of-tolerance alerts1912 may be initiated in real time by the management personnel.

In one implementation, operations monitoring application 1900 may beinstalled and executing on a computing device (not shown) that isseparate from locate receiver 1510, but in communication with the locatereceiver 1510, such as remote computer 150. In another implementation,operations monitoring application 1900 may be installed (in memory) andexecuting (via one or more processors) on a locate receiver itself, suchthe locate receiver 1510. In yet another implementation, certainfunctionality and/or components of operations monitoring application1900 may be installed and executing fully or in part on the combinationof a separate computing device and a locate receiver (e.g., locatereceiver 1510).

To facilitate operation of a locate receiver (e.g., locate receiver1510) with operations monitoring application 1900 of FIG. 19 when theapplication 1900 is executed partly or entirely on a separate computingdevice (e.g., remote computer 150), the locate receiver may have loadedthereon an operations monitoring client, which may be a counterpart tooperations monitoring application 1900. For example, the operationsmonitoring client may be executed by the processor 118 and may processinformation of operations monitoring application 1900. Alternatively,the operations monitoring client may comprise a combination of hardwareand software and/or firmware, which may be coupled to the locatereceiver to communicate with the processor 118. In such an embodiment,the software and/or firmware may process information of operationsmonitoring application 1900. Alternatively, as note above, the controlelectronics 112 of the locate receiver may include fully or in partoperations monitoring application 1900 itself. According to oneembodiment, the operations monitoring client is programmed to enable anddisable detection electronics 131 of the locate receiver 1510.

Table 17 shows an example of sensor data 1916 that may be returned fromenvironmental sensors 1520 and operational sensors 1530. Further, sensordata 1916 may include timestamp information, for example from the timingsystem 128.

TABLE 17 Example sensor data 1916 that may be returned from locatereceiver Quantity Data returned Timestamp 12-Jul-2008; 09:35:15.2Ambient temperature 73 degrees F. Surface temperature 78 degrees F.Humidity 31% Illuminance 1500 lux Altitude 105 meters Heading (fromcompass) 243 degrees Inclination −20 degrees Acceleration (x-axis) 0.285g Yaw rate 12 degrees/second Proximity 15 cm Pressure 65 psi Devicehealth sensor battery strength 67% Geo-location N35°43.57518,W078°49.78314 Image captured (Y/N) Y Audio captured (Y/N) N

Non-limiting examples of how the data provided by the environmentalsensors 1520 and operational sensors 1530 may be used by the operationsmonitoring application 1900 are now given. It should be appreciated thatnumerous other conditions may be detected and acted upon.

-   -   i. Readings from ambient temperature sensor 1602 may be used by        operations monitoring application 1900 to determine whether a        locate receiver is being used while in an out-of-tolerance        condition with respect to ambient temperature. If an        out-of-tolerance condition with respect to ambient temperature        is present, an example of the corresponding out-of-tolerance        alert 1912 may be “It is too cold (or too hot) to be locating.        Please acknowledge.”    -   ii. Readings from surface temperature sensor 1604 may be used by        operations monitoring application 1900 to determine whether a        locate receiver is being used above a surface whose temperature        is in an out-of-tolerance condition. If an out-of-tolerance        condition with respect to surface temperature is present, an        example of the corresponding out-of-tolerance alert 1912 may be        “The surface is too cold (or too hot) to be locating. Please        acknowledge.”    -   iii. Readings from humidity sensor 1606 may be used by        operations monitoring application 1900 to determine whether a        locate receiver is being used in an out-of-tolerance condition        with respect to humidity. If an out-of-tolerance condition with        respect to humidity is present, an example of the corresponding        out-of-tolerance alert 1912 may be “The humidity is too high to        be locating. Please acknowledge.”    -   iv. Readings from light sensor 1608 may be used by operations        monitoring application 1900 to determine whether locate        operations are being performed while in an out-of-tolerance        condition with respect to lighting. If an out-of-tolerance        condition with respect to lighting is present, an example of the        corresponding out-of-tolerance alert 1912 may be “There is        insufficient light to be performing locating operations        effectively and/or safely. Please acknowledge.”    -   v. Readings from location tracking system 130 may be used by        operations monitoring application 1900 to determine whether        locate operations are being performed in an out-of-tolerance        condition with respect to geo-location (e.g., at the wrong        location). If an out-of-tolerance condition with respect to the        geo-location is present, an example of the corresponding        out-of-tolerance alert 1912 may be “It appears that you are at        the wrong location. Please suspend operations and check the        location information on the locate request ticket. Please        acknowledge.”    -   vi. Readings from one or more operational temperature sensors        1702 may be used by operations monitoring application 1900 to        determine whether a component of the locate receiver is        overheating. An example of the corresponding out-of-tolerance        alert 1912 may be “Warning. The locate receiver is overheating.        Please turn off the device and allow it to cool. Please        acknowledge.”    -   vii. Readings from compass 1704 may be used by operations        monitoring application 1900 to determine whether the heading of        the locate receiver is out-of-tolerance. If an out-of-tolerance        condition with respect to heading is present, an example of the        corresponding out-of-tolerance alert 1912 may be “You appear to        be heading in the wrong direction. Please adjust course. Please        acknowledge.”    -   viii. Readings from inclinometer 1706 may be used by operations        monitoring application 1900 to determine whether the locate        receiver is being used in an out-of-tolerance condition with        respect to angle. If an out-of-tolerance condition with respect        to angle is present, an example of the corresponding        out-of-tolerance alert 1912 may be “The locate receiver angle is        too shallow (or too steep). Please adjust the angle to be about        perpendicular to target surface. Please acknowledge.”    -   ix. Readings from accelerometer 1708 may be used by operations        monitoring application 1900 to determine whether the locate        receiver is being used in an out-of-tolerance condition with        respect to the rate of movement and/or motion of the locate        receiver during the locate operation. If an out-of-tolerance        condition with respect to the motion is present, an example of        the corresponding out-of-tolerance alert 1912 may be “You are        sweeping the locate receiver too rapidly to pick up a signal        reliably. Please slow down the sweeping motion. Please        acknowledge.”    -   x. Readings from yaw rate sensor 1710 may be used by operations        monitoring application 1900 to determine whether the locate        receiver is being used in an out-of-tolerance condition with        respect to yaw rate. If an out-of-tolerance condition with        respect to yaw rate of the locate receiver is present, an        example of the corresponding out-of-tolerance alert 1912 may be        “You are twisting the locate receiver too quickly. Please        acknowledge.”    -   xi. Readings from proximity sensor 1712 may be used by        operations monitoring application 1900 to determine whether the        locate receiver is being used in an out-of-tolerance condition        with respect to the distance from the surface under which a        facility is located. If an out-of-tolerance condition with        respect to distance is present, an example of the corresponding        out-of-tolerance alert 1912 may be “The tip of the locate        receiver is too close (or too far) from the target surface.        Please adjust to between 3 and 6 inches from surface. Please        acknowledge.”    -   xii. Readings from the pressure sensor 1714 may be used by        operations monitoring application 1900 to determine whether the        actuation system of the locate receiver is being properly        actuated. In an out-of-tolerance condition with respect to        pressure is present, an example of the corresponding        out-of-tolerance alert 1912 may be “You are not pressing the        trigger firmly enough. Please acknowledge.”    -   xiii. In one embodiment the device health sensor 1716 may        monitor a battery level of the locate receiver. If an        out-of-tolerance condition with respect to the battery level is        detected by operations monitoring application 1900, an example        of the corresponding out-of-tolerance alert 1912 may be “The        battery of the locate receiver is too weak to perform locate        operations reliably. Please replace or recharge the battery as        soon as possible. Please acknowledge.”    -   xiv. Readings from the detection electronics 131 may be used by        operations monitoring application 1900 to determine whether the        locate receiver is being used in an out-of-tolerance condition        with respect to the frequency. If an out-of-tolerance condition        with respect to the frequency is present, an example of the        corresponding out-of-tolerance alert 1912 may be “The frequency        settings of the locate receiver and locate transmitter do not        match. Please check the frequency settings of your locating        equipment. Please acknowledge.”    -   xv. Signal strength readings from the detection electronics 131        may be used by operations monitoring application 1900 to        determine whether the locate receiver is being used in an        out-of-tolerance condition with respect to signal strength. If        an out-of-tolerance condition with respect to signal strength is        present, an example of the corresponding out-of-tolerance alert        1912 may be “The signal strength of the locate receiver is too        weak to be reliable. Please adjust the gain and/or frequency        settings of your locating equipment in an attempt to detect a        more reliable signal. Please acknowledge.”

Other conditions and events that may arise with the operationsmonitoring application 1900 and which may trigger an alert ornotification to the technician include, but are not limited to, thefollowing:

-   -   (a) User Input Errors—Action taken by the user, or suggested by        usage pattern is invalid for the current device configuration;    -   (b) System Malfunction Errors—locate receiver encountered a        problem while processing valid data, and was unsuccessful in        automatically correcting this problem;    -   (c) Storage Errors—Standard data cache of the locate receiver or        extended storage experiences some error in storing the current        data, such as insufficient storage space or some other storage        error;    -   (d) Power Errors—locate receiver has either exhausted the        battery supply (e.g., power source 114), or an unrecoverable        battery/power error was encountered;    -   (e) Network Errors—The network component (e.g., communication        interface 124) has experienced an unrecoverable error;    -   Geographic Location Errors—The GPS component (e.g., location        tracking system 130) has experienced an unrecoverable error;    -   (g) Actuator Errors—The actuator component (e.g., actuation        system 120) has experienced an unrecoverable error;    -   (h) Synchronization Errors—locate receiver encountered a problem        while synchronizing with the host server (e.g., computer 150)        and was unsuccessful in automatically correcting this problem;    -   (i) Data Accessibility Errors—The requested data cannot be        retrieved due to data corruption, cache locking, or missing        medium;    -   (j) User Input Required—Operator response is required prior to        continuing;    -   (k) Network Connectivity—The network component (e.g.,        communication interface 124) has detected a change in coverage        (coverage loss, overage gain, etc);    -   (l) Geographic Position Accuracy—The GPS component (e.g.,        location tracking system 130) has detected a change in overall        accuracy (gain or loss of satellite, WAAS support, etc).

In the examples above, alert acknowledgments 1918 in response toout-of-tolerance alerts 1912 may take various forms. In one example, thetechnician may acknowledge using the user interface 126, for example bypushing a button, flipping a switch, or selecting a menu option,depending on the type of user interface. Different user inputs (buttons,toggles, menu selections, etc.) may have different meanings with respectto providing alert acknowledgments 1918. Table 18 below shows an exampleof alert acknowledgments 1918, wherein, as a non-limiting example,certain keys of a user interface of the locate receiver have certainmeanings.

TABLE 18 Example alert acknowledgments 1918 Key Meaning # Indicates anacknowledgement that the alert is received * Indicates anacknowledgement that the alert is received and that corrective action isbeing or has been taken @ Indicates an acknowledgement that the alert isreceived and that locate operations are continuing regardless $Indicates an acknowledgement that the alert is received and that locateoperations are (temporarily) suspended

In another example, a dropdown menu and/or a set of icons that includethe various types of alert acknowledgments 1918, such as shown in Table18, may be presented on the display of the locate receiver. The user maythen select the desired type of alert acknowledgment 1918 from thedropdown menu and/or icons.

Also, as mentioned above, out-of-tolerance conditions and otherconditions detected by the environmental and/or operational sensors maybe logged, for example into alerts log 1908, irrespective of whether analert is provided to the technician. Thus, for any of theabove-described examples in which an alert may be generated, a log ofthe detected condition may also or alternatively be made. Also, otherconditions than those described above may be logged.

FIG. 20 is a functional block diagram of an example of a locateoperations system 2000 that includes operations monitoring application1900 of FIG. 19 and the locate receiver 1510 of FIG. 15. Again, otherlocate receivers or locate transmitters as described herein may be used,and locate receiver 1510 is described only for purposes of illustration.Locate operations system 2000 may include a central server 2010, whichis maintained and operated by, for example, a locate company, afacilities owner, a regulatory authority, or other agency (not shown).Central server 2010 may be any local or centralized computing devicethat is capable of hosting and facilitating execution of one or moreapplications. In implementation, central server 2010 may be a networkedapplication server and/or web server that is connected to a network2012. Examples of personnel that may be associated with central server2010 include locate technicians 2014.

Residing on central server 2010 may be business applications 2016, whichmay be any business applications that may be useful with respect tolocate operations. In one example, business applications 2016 mayinclude a locate operations scoring application 2018 that processesinformation about locate operations and generates locate operationsscores 2020 that may indicate the degree of quality of individual locateoperations. Additionally, SOP information 1902 may reside at centralserver 2010 and may be accessed by operations monitoring application1900 and/or any entity of locate operations system 2000 via network2012.

For example, locate operations scoring application 2018 may be based onvarious embodiments of a quality assessment application, as well as anyone or more of the scoring criteria and/or exemplary metrics disclosedin connection with such quality assessment applications, as set forth inU.S. Non-provisional application Ser. No. 12/493,109, filed Jun. 26,2009, entitled “METHODS AND APPARATUS FOR QUALITY ASSESSMENT OF A FIELDSERVICE OPERATION,” and published as U.S. Patent Publication2009-0327024-A1, which application is incorporated by reference herein.In particular, a quality assessment application may be configured toreceive a variety of information germane to locate and markingoperations, and compare such information to expected values orbenchmarks (metrics) based on various criteria. A scoring algorithmimplemented as part of some implementations of a quality assessmentapplication may compare various input information (e.g., “fieldinformation,” as obtained from one or more pieces of locating equipmentsuch as a locate receiver) to the expected values or benchmarks togenerate a quality assessment score in an automated fashion.

In another example, business applications 2016 may include a ticketapproval application 2022 that processes information about locate andmarking operations and generates ticket approval outcomes 2024 thatagain may indicate the degree of quality of individual locate andmarking operations. For example, ticket approval application 2022 may bebased on the ticket approval system that is described in U.S.Non-provisional application Ser. No. 12/204,454, filed Sep. 4, 2008,entitled “TICKET APPROVAL SYSTEM FOR AND METHOD OF PERFORMING QUALITYCONTROL IN FIELD SERVICE APPLICATIONS,” and published as U.S. PatentPublication 2009-0204466-A1, which application is hereby incorporatedherein by reference. This application describes a ticket approval systemfor and method of performing quality control (QC) in field serviceapplications. The ticket approval system may include a work managementserver. The work management server may include a ticket approvalsoftware application and a database for storing digital ticketinformation, such as field service site identification information,manifest information, and digital images of field service activities. Amethod of performing QC may include, but is not limited to, the fieldtechnician completing the ticket and providing data/images, an approverviewing and selecting a certain field technician and ticket for qualitycontrol review, the approver reviewing data/images of the selectedticket, the approver approving the ticket, the approver tagging theticket for QC, a QC approver processing QC referrals, the QC approverrouting the ticket to a QC technician, the QC technician completing theQC tasks and updating the data/images of the selected ticket, theapprover tagging the ticket for coaching, the approver processingcoaching referrals, and the approver performing coaching tasks.

Network 2012 may be, for example, any local area network (LAN) and/orwide area network (WAN) for connecting to the Internet. In onenon-limiting embodiment, network 2012 provides the communication linkbetween any and/or all entities of locate operations system 2000. Forexample, network 2012 provides the communication network by whichinformation may be exchanged between central server 2010, one or moreonsite computers 2030, and/or locating equipment (e.g., locate receiver1510) that are used by locate technicians 2014 in the field.

Onsite computers 2030 may be any computing devices that are capable ofprocessing and executing program instructions. Onsite computers 2030 maybe used by locate technicians 2014 that are performing locate andmarking operations in the field. For example, each onsite computer 2030may be a portable computer, a personal computer, a tablet device, apersonal digital assistant (PDA), a cellular radiotelephone, a mobilecomputing device, a touch-screen device, a touchpad device, or generallyany device including, or connected to, a processor and a user interface.Preferably, each onsite computer 2030 is a portable computing device,such as laptop computer or tablet device. Onsite computers 2030 may beused by locate technicians 2014 to process locate request tickets (notshown) and to perform locate and marking operations accordingly.

Additionally, operations monitoring application 1900 may be installed ononsite computers 2030. For example, operations monitoring application1900 may be used to process information received from or transmitted tolocate receiver 1510. Each onsite computer 2030 may include a processingunit 2032, which may be any standard controller or microprocessor devicethat is capable of executing program instructions, such as those fromoperations monitoring application 1900. Each onsite computer 2030 mayalso include a quantity of memory 2034, which may be any data storagemechanism for storing any information that is processed locally atonsite computer 2030. Processing unit 2032 and memory 2034 may be usedfor managing the overall operations of onsite computer 2030.

Further, each onsite computer 2030 may include a communication interface2038 for connecting to network 2012 and/or for communication withlocating equipment. For example, communication interface 2038 may be anywired and/or wireless communication interface by which information maybe exchanged between any entities of locate operations system 2000.

Operations monitoring application 1900 is used in locate operationssystem 2000 for detecting and monitoring the use of locating equipment(e.g., locate receiver 1510) in out-of-tolerance conditions, asdescribed above. For example, operations algorithm 1906 of operationsmonitoring application 1900 determines whether out-of-toleranceenvironmental and/or operational conditions are present during locateoperations and/or whether violations of certain process tolerances arepresent during locate operations. Optionally, operations monitoringapplication 1900 may be used to automatically enable and disable (eitherelectrically, mechanically, or both) locating equipment in the fieldbased on certain out-of-tolerance conditions being present.

Further, locate operations system 2000 is not limited to the types andnumbers of entities that are shown in FIG. 20. Any types and numbers ofentities that may be useful in underground facilities locateapplications may be included in locate operations system 2000. Moredetails of a method of detecting and monitoring the use of locatingequipment for out-of-tolerance conditions by use of locate operationssystem 2000 are described with reference to FIG. 21.

FIG. 21 illustrates a flow diagram of an example of a method 2100 ofdetecting and monitoring the use of locating equipment, such as thevarious locate receivers and transmitters described herein, forout-of-tolerance conditions utilizing, for example, locate operationssystem 2000 of FIG. 20. As noted above, the method may be implemented onany suitable combination of hardware, such as those items shown in FIG.20, or entirely on the locate receiver itself. Method 2100 may include,but is not limited to, the following steps, which may be implemented inany order.

At step 2110, onsite computer 2030 or the locate receiver itself maydetect powering up (e.g., a power on state), and/or one more specificevents (e.g., docking/de-docking of a locate receiver, one or moreactuations, error conditions, technician interaction with a userinterface, etc.) associated with a locate receiver, such as locatereceiver 1510. Additionally, the relevant SOP information is acquired.For example, using location tracking system 130 of locate receiver 1510,the geo-location of the job/work site may be determined. Based on thisgeo-location information, operations monitoring application 1900automatically queries SOP information 1902 at central server 2010 forthe SOP information of the regulatory body that corresponds to thelocation of the work site, which is used to inform operating limitstable 1904 of operations monitoring application 1900.

Subsequently, operations monitoring application 1900 at onsite computer2030 may begin monitoring the environmental and/or operating conditionsassociated with use of the locate receiver. For example, operationsalgorithm 1906 of operations monitoring application 1900 beginsmonitoring sensor data 1916 that is returned from locate receiver 1510and compares the contents of sensor data 1916 to information inoperating limits table 1904.

At decision step 2112, operations algorithm 1906 of operationsmonitoring application 1900 determines whether any out-of-toleranceconditions are present. For example, if any one of the followingout-of-tolerance conditions is present, method 2100 may proceed to step2116. However, if none of the following out-of-tolerance conditions arepresent, method 2100 may proceed to step 2114. The followingout-of-tolerance conditions are exemplary only and not meant to belimiting.

-   -   1. Readings from ambient temperature sensor 1602 may indicate an        out-of-tolerance condition with respect to ambient temperature        when compared against, for example, the maximum ambient        temperature and/or minimum ambient temperature specifications of        operating limits table 1904 (see, for example, Table 16).    -   2. Readings from surface temperature sensor 1604 may indicate an        out-of-tolerance condition with respect to surface temperature        when compared against, for example, the maximum surface        temperature and/or minimum surface temperature specifications of        operating limits table 1904 (see, for example, Table 16).    -   3. Readings from humidity sensor 1606 may indicate an        out-of-tolerance condition with respect to humidity when        compared against, for example, the maximum ambient humidity        specification of operating limits table 1904 (see, for example,        Table 16).    -   4. Readings from light sensor 1608 may indicate an        out-of-tolerance condition with respect to lighting when        compared against, for example, the minimum ambient light level        specification of operating limits table 1904 (see, for example,        Table 16).    -   5. Readings from compass 1704 may indicate an out-of-tolerance        condition with respect to heading when compared against, for        example, an expected value.    -   6. Readings from inclinometer 1706 may indicate an        out-of-tolerance condition with respect to locate receiver angle        when compared against, for example, the minimum angle and/or        maximum angle specifications of operating limits table 1904        (see, for example, Table 16).    -   7. Readings from accelerometer 1708 may indicate an        out-of-tolerance condition with respect to the rate of movement        and/or motion of the locate receiver when compared against, for        example, the maximum motion rate specification of operating        limits table 1904 (see, for example, Table 16).    -   8. Readings from yaw rate sensor 1710 may indicate an        out-of-tolerance condition with respect to yaw rate when        compared against, for example, the maximum yaw rate        specification of operating limits table 1904 (see, for example,        Table 16).    -   9. Readings from proximity sensor 1712 may indicate an        out-of-tolerance condition with respect to locate receiver        distance from a target surface when compared against, for        example, the minimum distance and/or maximum distance        specifications of operating limits table 1904 (see, for example,        Table 16).    -   10. Readings from pressure sensor 1714 may indicate an        out-of-tolerance condition with respect to the pressure exerted        on an actuation system of the locate receiver when compared        against, for example, the maximum pressure specifications of        operating limits table 1904 (see, for example, Table 16).    -   11. Information from the device health sensor 1716 that is        monitoring the battery of the locate receiver may indicate an        out-of-tolerance condition with respect to battery strength when        compared against, for example, the minimum battery strength        specification of operating limits table 1904 (see, for example,        Table 16).    -   12. Information from the detection electronics 131 may indicate        an out-of-tolerance condition with respect to frequency, for        example when compared against the locate receiver frequency        specification of operating limits table 1904 (see, for example,        table 16).    -   13. Information from the detection electronics 131 may provide        signal strength readings which may indicate an out-of-tolerance        condition with respect to signal strength when compared to, for        example, the signal strength specifications of operating limits        table 1904 (see, for example, table 16).

At step 2114, operations monitoring application 1900 continues tomonitor the conditions (e.g., environmental and/or operating) of thelocate receiver during locate operations. For example, operationsmonitoring application 1900 at onsite computer 2030 continues to monitorthe conditions of the locate receiver 1510 during locate operations bycomparing the contents of sensor data 1916 to information in operatinglimits table 1904. At the conclusion of this step, method 2100 may, forexample, return to step 2112.

At step 2116, operations monitoring application 1900 generates thecorresponding out-of-tolerance alert 1912, logs the out-of-tolerancealert 1912 in alerts log 1908, and transmits the out-of-tolerance alert1912 to the locating equipment, such as to locate receiver 1510, inthose embodiments in which the method is not entirely implemented on thelocate receiver itself. By way of example, the followingout-of-tolerance alerts 1912 correspond respectively to the exampleout-of-tolerance conditions of step 2112. The following out-of-tolerancealerts 1912 are exemplary only and not meant to be limiting. Also, thebelow-indicated alerts with respect to surface temperature and humiditymay be applicable to scenarios in which a locate technician is bothlocating and marking a facility.

-   -   1. “It is too cold (or too hot) to be locating. Please        acknowledge.”    -   2. “The surface temperature is too cold (or too hot) to dispense        marking material. Please acknowledge.”    -   3. “The humidity it too high to be locating and/or dispensing        marking material. Please acknowledge.”    -   4. “There is insufficient light to be performing locate        operations effectively and/or safely. Please acknowledge.”    -   5. “You appear to be heading in the wrong direction. Please        acknowledge.”    -   6. “Receiver angle is too shallow (or too steep). Please adjust        the angle to be about perpendicular to target surface. Please        acknowledge.”    -   7. “Locating (sweeping) motion is too rapid or too erratic to        pick up a signal reliably. Please slow down or smooth out the        motion. Please acknowledge.”    -   8. “Locate receiver is being twisted too quickly. Please        acknowledge.”    -   9. “The tip of the locate receiver is too close (or too far)        from the target surface. Please adjust to between 3 and 6 inches        from surface. Please acknowledge.”    -   10. “You are applying too much pressure to the actuator. Please        acknowledge.”    -   11. “The battery of the locate receiver is too weak to perform        locate operations reliably. Please replace or recharge the        battery as soon as possible. Please acknowledge.”    -   12. “The frequency settings of the locate receiver and the        locate transmitter do not match. Please check the frequency        settings of your locating equipment. Please acknowledge.”    -   13. “The signal strength of the locate receiver is too weak to        be reliable. Please adjust the gain and/or frequency settings of        your locating equipment in an attempt to detect a more reliable        signal. Please acknowledge.”    -   At step 2118, one or more out-of-tolerance alerts 1912 are        received at the locating equipment, such as locate receiver        1510, in those embodiments in which alerts are not generated on        the locate receiver itself. The out-of-tolerance alerts 1912 may        be presented to the user in, for example, text form via a        display of the locate receiver, audible form (e.g., synthesized        speech provided by a text-to-speech synthesizer of the locate        receiver) via a speaker of the locate receiver, or in any other        suitable manner.

At step 2120, a certain alert acknowledgment 1918 may be returned tooperations monitoring application 1900. For example, the user, such as acertain locate technician 2014 may press a certain key of the userinterface of the locate receiver and initiate the desired alertacknowledgment 1918, such as those shown above in Table 18. Once thealert acknowledgment 1918 is received at operations monitoringapplication 1900, it may be associated with its originatingout-of-tolerance alert 1912 and logged in alerts log 1908. Subsequently,operations monitoring application 1900 continues to monitor theconditions of the locating equipment, such as locate receiver 1510. Atthe conclusion of this step, method 2100 may, for example, return tostep 2112 and may optionally proceed to step 2122.

Optionally, method 2100 may include steps to disable locating equipment(e.g., by disabling the actuation system, the detection electronics, orany other component of the locating equipment) until or unless a certainout-of-tolerance condition is corrected. For example, method 2100 mayoptionally include the following steps.

At optional decision step 2122, certain out-of-tolerance conditions maycarry such importance that the suspension of locate operations ismandated (e.g., disable actuations so as to impede the technician fromcontinuing). One such out-of-tolerance condition may be theout-of-tolerance condition with respect to temperature. Another suchout-of-tolerance condition may be the out-of-tolerance condition withrespect to humidity. Yet another such out-of-tolerance condition may bethe out-of-tolerance condition with respect to lighting. Still anothersuch out-of-tolerance condition may be the out-of-tolerance conditionwith respect to acceleration or velocity. Other out-of-toleranceconditions may also be sufficiently important to mandate suspendinglocate operations, and those examples listed are non-limiting. In theseexamples, operations monitoring application 1900 may wait a certainamount of time (e.g., 1 minute) from the initial detection of theout-of-tolerance conditions and again acquire sensor data 1916 todetermine whether the out-of-tolerance condition is still present or hasbeen corrected. If the out-of-tolerance condition has been corrected,method 2100 may proceed to step 2124. However, if the out-of-tolerancecondition has not been corrected, method 2100 may proceed to step 2126.

At optional step 2124, the locate technician 2014 continues to performlocate operations and operations monitoring application 1900 continuesto monitor the conditions of the locate receiver. At the conclusion ofthis step, method 2100 may, for example, return to step 2112.

At optional step 2126, the locate receiver may be disabled. For example,actuation system 120 of locate receiver 1510 may be disabled to impedeuser acuations and/or detection electronics 131 may be disabled. Theaction to disable may be logged in alerts log 1908.

At any time during the steps of method 2100, the contents of alerts log1908 may be processed by business applications 2016. In one example,alerts log 1908 may be processed by locate operations scoringapplication 2018 and/or ticket approval application 2022 for assessingthe quality of locate and marking operations that are performed in thefield, assessing the skill and/or competency levels of locatetechnicians, and the like.

While FIGS. 19-21 illustrate some non-limiting examples of manners inwhich data provided by environmental sensors and/or operational sensorsof a locate receiver may be used, other uses are also possible. Forexample, the data from environmental sensors 1520 and/or operationalsensors 1530 may be used to trigger alerts or notifications to atechnician irrespective of whether the sensed condition is outsidetolerances. For example, in some instances there may not be a specifictolerance for a given environmental or operational condition, and yet analert to the technician may be generated for the purpose of making thetechnician aware of whatever value the sensed condition has taken. Thus,the generation of alerts/notifications/warnings based on sensedenvironmental and operational conditions is not limited to thoseinstances in which the sensed condition takes any particular value(s).Furthermore, alerts may be generated based on conditions relating todispensing of a marking material, which may be applicable to scenariosin which a technician is both locating and marking a facility. Forexample, sensed conditions with respect to ambient temperature, surfacetemperature, and/or humidity, among others, may impact dispensing of amarking material, and thus alerts/notifications may be presented to thetechnician to indicate whether conditions are appropriate for or adverseto dispensing of a marking material. Also, as previously explained, thealert/notification signal(s) described herein may take any suitableform(s), such as an audible alert (a chime, a ring tone, a verbalmessage or command (e.g., synthesized speech provided by atext-to-speech synthesizer of the locate receiver), etc.), a visualalert (e.g., a text display (for example, in those embodiments in whichthe locate receiver includes a display), an indicator light, etc.), atactile indication, any combination of those options, or any othersuitable type of notification.

Also, it should be appreciated that information from one or more of theenvironmental sensors 1520 and/or operational sensors 1530 may be usedmore generally to control or alter operation of the locate receiver. Forexample, one or more components of the locate receiver 1510 may beactivated, enabled, or disabled, or the functionality thereof controlledor altered in some manner, in response to one or more of theenvironmental sensors 1520 and/or operational sensors 1530 providingenvironmental information and/or operational information indicative thatsuch control should be exhibited. Such activation, enablement, and/ordisablement may be electrical in nature (e.g., providing power or anenable signal, triggering operation of a sensor, etc.), mechanical innature (e.g., causing a locking mechanism to be engaged on the actuationsystem) or both. For example, if the sensed inclination of the locatereceiver as sensed by inclinometer 1706 is unsuitable for locating, theactuation system 120 and/or detection electronics 131 may be disabled.Similarly, if the acceleration as sensed by accelerometer 1708 isout-of-tolerance with accepted practices, the actuation system 120and/or detection electronics 131 may be disabled. If a sensed conditionis out-of-tolerance, the operation of one of the environmental and/oroperational sensors may be altered, for example by altering the samplingrate to collect more or less data. According to one embodiment, thesampling rate of a location tracking system of the locate receiver maybe increased in response to an out-of-tolerance heading detected by thecompass of the locate receiver. According to another embodiment, thesampling rate of the location tracking system may be increased inresponse to the location tracking system detecting an out-of-tolerancelocation. Other control actions are also possible, and the aspectsdescribed herein relating to controlling the locate receiver in responseto sensing environmental and/or operational conditions are not limitedin the types of actions that may be taken or the sensed conditions whichmay trigger action/alteration.

Furthermore, the determination of whether a condition or multipleconditions are out-of-tolerance, whether to generate an alert ornotification to a technician, or whether to control/alter somefunctionality of the locate receiver based at least in part onenvironmental and/or operational information, may be made in anysuitable manner. For instance, as illustrated in some of the foregoingexamples, such a determination may be made by comparison of a singlevalue from a sensor to an expected or target value. Alternatively,outputs from the environmental sensors and/or operational sensors may bemonitored for changes (e.g., any change, or by some predeterminedamount), rather than for a particular single value. For example, achange in temperature, or a change in light, may initiate generation ofan alert, rather than a single temperature or light value.

In addition, information provided by one or more of the environmentalsensors and/or operational sensors may be monitored and analyzed todetect patterns. For example, information provided by the operationalsensors may be used to formulate and assess patterns of operation of aparticular technician, which may be thought of as technician“signatures.” As an example, a particular technician may have acharacteristic motion when performing a locate operation, such as whensweeping over a buried facility, or may perform the operation at acharacteristic speed. Assessing information provided by the one or moreaccelerometers 1708, for example, may allow for determination of theunique characteristic. Once determined, information from the operationalsensors on future jobs may allow for identification of the technicianbased on the unique characteristic, and may also be used to assesswhether the technician is operating in his/her normal manner or whetherhe/she is deviating from his/her usual operation, which may suggest thatthe technician was doing something out of the ordinary, and whichaccordingly may cause generation of an alert/notification and/oralteration of the locate receiver. Such information, therefore, may beused for quality control and/or for training purposes of technicians.Similarly, such operating information from multiple technicians may beused to develop standard operating guidelines or protocols.

It should be appreciated from the foregoing discussion that informationprovided by two or more of the environmental sensors may be used incombination, for example to assess the environmental conditions, tointeract with the technician (e.g., generate an alert), and/or tocontrol/alter operation of the locate receiver (e.g., disable or enableactuation of the locate receiver). As a non-limiting example, the sensedambient temperature in combination with the sensed humidity may provideinformation about whether a particular form of precipitation is present(e.g., snow, rain, etc.), in response to which an alert may be generatedand/or one or more components of the locate receiver may be enabled ordisabled (e.g., the actuation system may be disabled). Non-limitingexamples of useful combinations of environmentally sensed conditionsinclude: ambient temperature+humidity; surface temperature+humidity;ambient temperature+surface temperature; ambient temperature+lightsensor; light+image capture; light+audio capture; and ambienttemperature+humidity+light. However, it should be appreciated that othercombinations are also possible.

It should also be appreciated from the foregoing discussion thatinformation provided by two or more of the operational sensors may beused in combination, for example to assess the operational conditions ofa locate receiver, to interact with the technician, to assess, determineand/or analyze technician “signatures” associated with deviceuse/manipulation, and/or to control or alter operation of the locatereceiver (e.g., to disable actuation of the locate receiver, enableactuation of the locate receiver, etc.). Non-limiting examples of usefulcombinations of sensed operational conditions which may be used for anyof the purposes described above include: acceleration of locatereceiver+proximity of locate receiver to surface; proximity of locatereceiver to surface+inclination of locate receiver;acceleration+heading; geo-location+heading+acceleration; andgeo-location+acceleration+inclination. However, it should be appreciatedthat other combinations are also possible.

Furthermore, according to one embodiment, information provided by one ormore environmental sensors may be used in combination with informationprovided by one or more operational sensors, for example to assess thequality of the locate operation, to interact with the technician, toassess, determine and/or analyze technician “signatures” associated withdevice use/manipulation, and/or to control or alter operation of thelocate receiver (e.g., disable or enable actuation of the locatereceiver). For example, information about ambient light level sensed bya light sensor may be used in combination with acceleration data from anaccelerometer, as, for example, it may be preferable in some embodimentsfor a technician to move more slowly in low light conditions. Othercombinations of sensor information may also be useful depending on aparticular application.

VIII. Group Mode and Solo Mode

As previously explained, the locate receivers described herein may beused in different modes, examples of which include locate mode andlandmark mode. In addition, locate receivers according to one aspect ofthe present invention may be operated in a so-called “solo mode” or aso-called “group mode.”

For some locate operations, a single technician may be present at thejobsite and may complete the locate operation. Thus, any locate datacollected relating to the job may be solely from the technician's locatereceiver and may not need to be combined with locate data from any otherlocate receivers. In such situations, the locate receiver may beoperated as an individual, independent locate receiver in solo mode. Asdescribed above, data collected by the locate receiver may be storedlocally and/or transmitted to a host server, such as remote computer150.

For certain types of underground facility locate operations, multiplelocate technicians may be working on a same locate ticketsimultaneously. When this occurs, it may be advantageous for some or allof the locate receivers that are used during performance of the ticketedjob to consolidate data, such as by providing data to a host server.This may be accomplished through the use of a group mode of operation ofthe locate receivers. In group mode, a locate receiver may act as a“worker” device, and may not be capable of transmitting its collectedlocate data to a remote computer. For example, the wireless transmissioncapability of the locate receiver may be disabled in group mode. Rather,the locate data may be cached in local memory 122 of the locatereceiver, or may be transmitted to another locate receiver, which mayact as a “leader” device, receiving the collected locate data from theother locate receivers used for the locate operation. The leader locatereceiver may then transmit the collected locate information to a remotecomputer, or may handle the collected information in any suitablemanner.

Selection of solo mode and group mode may be accomplished in anysuitable manner. For example, selection between these two modes may befacilitated by any suitable combination of hardware and/or software onthe locate receiver. For example, the locate receiver may include modecontroller software for selecting the operating mode of the locatereceiver. According to one embodiment, the user interface of the locatereceiver may include a toggle switch for toggling between solo mode andgroup mode. Alternatively, the locate receiver may present thetechnician with a menu on a graphical display of user interface 122,from which the technician may choose the desired mode. Other schemes forallowing selection of solo mode and group mode are also possible.

IX. Enhancements to Determination of Location of Locate Receiver

According to some embodiments, it may be desirable to know the locationof the tip of the locate receiver, as for example, the tip may be theportion of the locate receiver located in close proximity to the groundwhen a locate technician sweeps the locate receiver over the ground todetect a buried facility. Thus, for example, determining the motion ofthe tip of the locate receiver may allow for assessment of technicianmanipulation of the locate receiver, which may be used for qualitycontrol, training purposes, and standard setting, among other things.Thus, according to another aspect of the present invention, methods andapparatus are provided for determining the location of the tip of alocate receiver. However, it should be appreciated that the tip of thelocate receiver is a non-limiting example of a specific point ofinterest of a locate receiver for which it may be desirable to know thelocation, as, for example, other portions of the locate receiver may beof interest in other embodiments. The methods and apparatus describedherein may be applied equally well to the determination of any point ofinterest on the locate receiver.

One approach for determining the location of the tip of the locatereceiver (e.g., tip 148 shown in FIG. 5), or any other point of intereston the locate receiver, is to place a location tracking system at thatpoint. Thus, according to one embodiment, a locate receiver, such as anyof the locate receivers described previously herein, or any other locatereceiver, may include a location tracking system 130 as discussed inother embodiments (e.g., a GPS receiver), wherein the location trackingsystem is disposed at or sufficiently near the tip of the locatereceiver, allowing for determination of the location of the tip of thelocate receiver. Thus, the location tracking system 130 may provide thegeo-location of the tip of the locate receiver, which, as mentioned, maybe useful for a variety of reasons. For example, the geo-locationinformation provided by the location tracking system may be used torecord the motion of the tip of the locate receiver, which may be usedfor detection of out-of-tolerance operation of the locate receiver,determination of operating patterns of technicians, or for various otherpurposes.

While the above-described embodiment provides a location tracking systempositioned at the point of interest on the locate receiver, suchpositioning of a location tracking system may not always be possible oradvantageous. For example, as explained previously herein, in someembodiments the operation of the location tracking system may befacilitated by positioning the location tracking system toward the topof the locate receiver, for example if the location tracking system is aGPS receiver. However, as mentioned, it may be desirable in someembodiments to determine the location of the tip of the locate receiver,or any other point of interest of the locate receiver, which in somesituations will not correspond to the top of the locate receiver. Thus,according to one embodiment, methods and apparatus are provided fordetermining the location of a point of interest of a locate receiverwhen a location tracking system is located at a different point on thelocate receiver. For simplicity of explanation, the following exampleswill be discussed assuming that a location tracking system is locatednear the top of the locate receiver and that the point of interest ofthe locate receiver is the tip of the locate receiver. It should beappreciated that the described apparatus and techniques may applyequally well to other positions of the location tracking system andpoints of interest on the locate receiver.

To facilitate the following discussion, it is useful to first considerthe physical configuration at issue for determining the location of thetip of the locate receiver when the location tracking system is locatedat or near the top of the locate receiver. For this purpose, the locatereceiver may be represented in simplified form as an elongated rod orstick. FIG. 22 illustrates a perspective view of such a simplifiedrepresentation of a locate receiver, shown as locate receiver 2200.

In FIG. 22, the x-y plane represents the ground and the z-directionrepresents the vertical direction perpendicular to the ground. The pointP1 may be the location of a location tracking system (e.g., a GPSreceiver), and in some embodiments may correspond generally to the topof the locate receiver, for example near where the technician may holdthe locate receiver if it is a handheld device. The point P2 representsthe point of interest of the locate receiver, and in this non-limitingexample corresponds generally to the tip of the locate receiver. Thepoint P2 may be assumed to be at ground level, i.e., in the x-y plane(z=0) for purposes of simplicity, except as described below in thoseembodiments in which the distance of P2 from the x-y plane may bemeasured. The shortest distance between P1 and P2 is given by L, whichin some embodiments may correspond to the length of the locate receiver,although not all embodiments are limited in this respect. For example,if the locate receiver has a non-linear shape, the distance L may notcorrespond to the length of the locate receiver. The locate receiver2200 may be projected onto the x-y plane (z=0) along the dashed line2202, which therefore lies in the x-y plane. The distance between thepoints P1 and P2 in the x-y plane (i.e., along the dashed line 2202) isrepresented by d. The distance between the point P1 and ground is givenby H (i.e., z=H). At any given time, the locate receiver may make anangle θ with respect to the x-y plane, i.e., with respect to ground inthis non-limiting example. The projection of the locate receiver on thex-y plane, i.e., along the line 2202, may be at an angle φ in the x-yplane with respect to the x axis. In some embodiments, the x-axis may bedefined to align with true North, although all embodiments are notlimited in this respect.

According to one embodiment, a locate receiver, such as locate receiver2200 may comprise a location tracking system at the point P1. Thelocation tracking system may provide the geo-location of the point P1with respect to the x-y plane, represented as GPS₀. The geo-location ofP2 in the x-y plane may be represented by GPS′. As will be explained,GPS′ may be determined based on a value of GPS₀ given by a locationtracking system and determination of suitable combinations of L, d, H,θ, and φ. The value of L may be known before the locate operationbegins, for example since it may be set after manufacture of the locatereceiver. The values of d, H, θ, and φ may be directly sensed duringoperation of the locate receiver or may be calculated using suitableones of the operational sensors 1530, as will be described below.

According to one embodiment, the geo-location of the tip of a locatereceiver, such as locate receiver 2200, may be determined using thevalue of GPS₀ given by the location tracking system at P1 andaccelerometer data from an accelerometer positioned at or sufficientlynear the tip of the locate receiver (i.e., at point P2 in FIG. 22). Inthis embodiment, it is assumed that the value of L is known ordetermined in any suitable manner. The accelerometer in thisnon-limiting embodiment is a 3-axis accelerometer. By suitable analysisof the acceleration values for each axis, using known algorithms, theangle θ that the locate receiver 2200 makes with the ground may bedetermined (see, e.g., the previous discussion of how to use anaccelerometer as an inclinometer, as described by Shanghai VigorTechnology Development Co.). Based on the known distance L and thedetermined angle θ, the distance d between GPS₀ and GPS′ in the x-yplane may be calculated (using the fact that the cosine of θ is equal tod/L).

Once the distance d is known, the value of GPS′ may be derived from GPS₀if the angle φ is known, since φ may provide the direction from GPS₀ toGPS′ (again, in some embodiments the x-axis may be aligned with, ortaken as, true North, such that φ may represent an angle with respect totrue North). The value of φ may be determined in one of several manners.One manner for determining φ is from the readout of a compass of thelocate receiver, such as previously described compass 1704. If thelocation tracking system providing GPS₀ is a GPS receiver, then thevalue of φ may alternatively be taken from the heading informationprovided as part of the NMEA data stream provided by the GPS receiver. Athird alternative for determining φ is to calculate a direction ofmotion based on multiple GPS points taken from the location trackingsystem. According to this third alternative, multiple GPS points takenat different times may be used to calculate a direction of motion by,for example, determining the direction indicated by a straight lineconnecting the multiple GPS points. Other methods for determining φ arealso possible, as these are non-limiting examples. Once φ is known, thevalue of GPS′ may then be determined from GPS₀, d and φ. Once GPS′ isdetermined, it may be used instead of GPS₀ (or in addition to GPS₀) asmore accurate geo-location data, which may be included, for example, inone or more event entries and/or electronic records as discussed above.

According to an alternative embodiment, the value of GPS′ may bedetermined from a measured value of GPS₀ using an inclinometer on thelocate receiver, such as inclinometer 1706, previously described. Theinclinometer may provide the value of θ. In this embodiment, it isassumed that the value of L is known or determined in any suitablemanner. Thus, the value of d may be determined using L and θ, asexplained above. The value of φ may be determined in any suitablemanner, for example using any of the techniques described above. Thevalue of GPS′ may then be determined from GPS₀, d, and φ, as notedabove.

According to another embodiment, the value of GPS′ may be determinedfrom a measured value of GPS₀ using a proximity sensor, such aspreviously described proximity sensor 1712. In this embodiment, it isassumed that the value of L is known or determined in any suitablemanner. The proximity sensor may be positioned at P1 and configured tomeasure the value of H. Assuming that the point P2 is at or very nearthe ground (i.e., having a vertical height of approximately zero), thevalue of H and the known distance L of the locate receiver may be usedto determine d, for example using the Pythagorean theorem. The value ofφ may be determined in any suitable manner, for example using any of thetechniques described above. The value of GPS′ may then be determinedusing GPS₀, d, and φ.

As explained, the above-described example, in which a single proximitysensor is used to determine the value of H, may provide suitable resultswhen it is assumed that the point P2 has zero vertical height. In oneembodiment, that assumption may be avoided by also including a proximitysensor at the point P2 and configured to measure the distance between P2and the ground. Then, the difference in height between P1 and P2 (ratherthan the value of H) may be used in connection with the known distance Lto determine the distance d (e.g., using the Pythagorean Theorem). Thevalue of φ may be determined in any suitable manner, for example usingany of the techniques described above. The value of GPS′ may then bedetermined using GPS₀, d, and φ.

According to a further alternative embodiment, the value of GPS′ may bedetermined from a measured value of GPS₀ using two 3-axis accelerometerson the locate receiver. One accelerometer may be located at the point P1on the locate receiver, while the second may be located at the point P2.Using the techniques described in U.S. Patent Application Publication2008/0255795, which is incorporated herein by reference in its entirety,the location of P2 relative to P1 may be determined.

As mentioned, in some instances it may be desirable to track the motionof a specific portion of a locate receiver, such as the tip of thelocate receiver, for any one of the reasons previously described. Inthose embodiments in which the locate receiver includes a locationtracking system providing a value of GPS₀ for a different point on thelocate receiver than the point of interest, the tracking of the point ofinterest may be performed by determining GPS′ (the location of the pointof interest) for each value of GPS₀ as the locate receiver is movedusing any of the above-described techniques.

However, in some instances, the value of GPS₀ provided by the locationtracking system may not have sufficient accuracy to allow for a desiredlevel of accuracy in tracking the motion at the desired point on thelocate receiver (e.g., the point P2). For example, when performing alocate operation, a technician may move the locate receiver by distancesthat are relatively small compared to the resolution of the locationtracking system. For example, when sweeping the locate receiver over theground, the sweeping pattern may include segments smaller than theresolution of the location tracking system (e.g., smaller thanapproximately 30 inches in some embodiments). In such instances, usingthe above-described techniques for determining GPS′ as the point P2moves may not sufficiently capture the movement with a desiredresolution. Thus, the techniques described below may be used.

According to one embodiment, the motion of the point P2 may be trackedby using any of the above-described techniques to get an initial valueof GPS′ and then using data from an accelerometer at the point P2 todetermine the distance traveled in the x and y directions. Thistechnique is commonly referred to in the relevant arts as “deadreckoning.” In this embodiment, the accelerometer may provideacceleration data for the x and y axes. That data may be integratedtwice to determine the total distance traveled in the x and ydirections, thus giving the position of P2 at any point in time relativeto any initial GPS′ value. Alternatively, the accelerometer may outputvelocity data for each axis, which may be integrated to determine thetotal distance traveled in the x and y directions. A specific example isnow described with respect to FIG. 23.

FIG. 23 illustrates a top view of a non-limiting example of a pattern ofmotion 2300 that may be made by a technician using one of the locatereceivers described herein. The illustrated pattern is shown forpurposes of illustration only, as it should be appreciated that variouspatterns and sweeping motions may be made by a technician using a locatereceiver.

The pattern of motion 2300 comprises lines 2302 a-2302 f. The solidlines in FIG. 23 correspond to when the actuation system of the locatereceiver (e.g., actuation system 120) is activated. Lines 2304 a and2304 b, described below, are shown as dashed lines because the actuationsystem is not actuated as the locate receiver traversed the pathsindicated by those lines.

The making of the pattern of motion 2300 by a locate receiver may bedetermined as follows. First, the technician may begin the pattern atthe point R1, at which time the technician actuates the actuation system(e.g., to record magnetic field data). The location of point R1 maycorrespond to the initial location of the tip of the locate receiver andtherefore may be determined from a value of GPS₀ of the top of thelocate receiver and any of the above-described techniques fordetermining the location of the tip relative to the location of the topof the locate receiver.

The technician may then begin to move the locate receiver along the pathindicated by line 2302 a, ending at the point R2. The motion of the tipof the locate receiver along line 2302 a may be determined from theoutput of an accelerometer at the tip of the locate receiver, providingan output signal for both the x and y directions. According to oneembodiment, the output of the accelerometer is velocity data for boththe x and y axes, and is output periodically, for example twice persecond, although higher and lower data output rates are possible. Thevelocity values for each of the x and y axes may be multiplied by thetime duration between samples of the accelerometer (e.g., one-half of asecond in this non-limiting example) to get the distance traveled in thex and y directions from the initial point R1. Alternatively, the totalvelocity of the locate receiver may be multiplied by the time durationbetween samples of the accelerometer, and the direction of motion may bedetermined by comparing the velocity values for the x and y axes to eachother, e.g., by taking the ratio of the velocity along the x-axis to thevelocity along the y-axis. Either way, the distance travelled in the xand y directions may be determined.

In the non-limiting example of FIG. 23, the first line, i.e., line 2302a, may serve as a base line or reference line, from which the angle ofsubsequent motions may be referenced. Thus, in FIG. 23, the angle of thesecond motion of the technician, from points R2 to R3 along the pathindicated by line 2304 a may be determined by reference to the directionof line 2302 a since the accelerometer output will indicate a changefrom the motion along the path of line 2302 a. The distance anddirection of the line 2304 a may be determined as described above forline 2302 a. Again, the line 2304 a is shown as a dashed line, as theactuation system of the locate receiver is not activated while thelocate receiver traverses the illustrated path.

The locate receiver is subsequently moved along line 2302 b (from pointR3 to R4), then along line 2304 b (from point R4 to R5), then along line2302 c (from point R5 to R6), along line 2302 d (from point R6 to R7),along line 2302 e (from point R7 to R8), and finally along line 2302 f(from point R8 back to point R5). The length and relative direction ofeach of the indicated lines may be determined as described above forline 2302 a.

Thus, it should be appreciated that according to this non-limitingembodiment, a value of GPS₀ provided by a location tracking system isused only to determine the initial location of R1, after which thelocations of point R2-R8 are determined using dead reckoning.

Also, it should be appreciated that while the relative orientation ofeach of the indicated lines is determined from the dead reckoningtechniques described, the absolute, or actual, orientation is notdetermined from the accelerometer data since the actual orientation ofline 2302 a is not determined from the accelerometer data. Thus,according to one embodiment an additional step of determining an actualorientation of the line 2302 a may be performed. According to onenon-limiting embodiment, the actual orientation of line 2302 a may begiven by a heading provided by a compass of the locate receiver whilethe line 2302 a is made. Other techniques may alternatively be used todetermine the actual direction of the first motion of the pattern ofmotion.

According to the above-described embodiment, the location of the tip ofa locate receiver may be determined by determining an initial locationusing a location tracking system and subsequently using the deadreckoning techniques described. Because the error associated with deadreckoning may increase as the distance traversed increases, it may bedesirable in some embodiments to “reset” the dead reckoning bydetermining a new initial location value using a location trackingsystem. For example, referring to the pattern of motion 2300, in oneembodiment the location of R1 may be determined from a value of GPS₀given by a location tracking system and any of the techniques describedfor determining a value of GPS′ for the given GPS₀. Subsequently, deadreckoning may be used to determine the paths of lines 2302 a, 2304 a,2302 b, and 2304 b. According to one embodiment, the location of pointR5 is not determined from dead reckoning, but rather may be determinedby getting a value of GPS₀ at the point R5 and calculating acorresponding value of GPS′. Then, dead reckoning may be used todetermine the locations of lines 2302 c-2302 f. In this manner, locationerrors that accumulate using dead reckoning may be minimized oreliminated.

Accordingly, it should be understood that a new initial location pointserving as a starting point for the use of dead reckoning may be set atany suitable intervals during a locate operation. Suitable criteria fordetermining when to set a new initial location point for the use of deadreckoning include setting a new initial point for the beginning of eachnew motion of a pattern that a technician makes (e.g., each new sweepingsegment of a sweeping pattern), for each new pattern, for each newlocate job, or every time the dead reckoning data indicates a thresholdtotal distance has been traveled (e.g., 5 meters, 10 meters, 50 meters,or any other threshold value). This list is not exhaustive, as othercriteria may also be used to determine when to set a new initiallocation point for the use of dead reckoning.

X. Enhanced User Interface

According to one aspect of the present invention, a locate receiver mayinclude an enhanced user interface with tactile functionality. As willbe described, the tactile functionality may be provided in one or moreof various locations on the locate receiver, and may be used for variouspurposes.

FIG. 24 illustrates an example of a portion of a locate receiver 2400including multiple tactile indicators for providing a tactile indicationto a technician using the locate receiver. The locate receiver 2400 maybe a locate receiver according to any of the embodiments previouslydescribed herein. The locate receiver 2400 includes a body 2410, controlelectronics 2412, a handle 2414 and an actuator 2416. In addition, thelocate receiver 2400 includes a user interface including a display 2418,a joystick 2420, and arrow selection buttons 2422. As compared to theuser interfaces of the locate receivers previously described, the userinterface of the locate receiver 2400 also includes three tactileindicators, 2424 a-2424 c, which may alternatively be referred to asvibrating devices or vibrators.

The tactile indicator 2424 a is disposed within or on the handle 2414 ofthe locate receiver 2400, or otherwise mechanically coupled to thehandle 2414. The tactile indicator 2424 b is disposed within or on thejoystick 2420, or is otherwise mechanically coupled to the joystick2420. The tactile indicator 2424 c is disposed within or on the actuator2416, or otherwise mechanically coupled to the actuator 2416. It shouldbe appreciated that locate receivers including tactile indicatorsaccording to the embodiments described herein are not limited to havingany particular number of tactile indicators (i.e., one or more) and arenot limited in the locations at which the tactile indicators are placed.

The tactile indicators may be of any suitable type. One example of asuitable type of tactile indicator is that used in cellular telephonesto provide the “vibrate” functionality. According to one embodiment, oneor more of the tactile indicators is formed by a flywheel that has aweight configured to unbalance the flywheel, so that when the flywheelspins it wobbles. According to one embodiment, all three of the tactileindicators are the same type, although not all embodiments are limitedin this respect.

The tactile indicators 2424 a-2424 c may provide any suitable type oftactile indication to a technician, in terms of duration, frequency,intensity, pattern, and any combinations thereof. Also, the tactileindicators 2424 a-2424 c need not provide the same type of tactileindication. For example, tactile indicator 2424 a may provide arelatively strong, continuous vibration of long duration, whereastactile indicator 2424 b may provide a series of low intensity, shortvibrations. Furthermore, one or more of the tactile indicators may beconfigurable to provide multiple different types of tactile indications.For example, in some instances the tactile indicator 2424 a may providea long, continuous vibration, whereas in other instances the tactileindicator 2424 a may provide a short vibration. Thus, the type(s) oftactile indication presented by the tactile indicators is not limiting.

According to one embodiment, the tactile indications provided to a usermay have different meanings. According to one embodiment, the meaningmay differ depending on the tactile indicator providing the tactileindication. For example, vibration of the tactile indicator 2424 a mayindicate the locate receiver power supply is low, while vibration of thetactile indicator 2424 b may indicate the technician has tried to selectan invalid entry for a menu displayed on display 2418, and vibration ofthe tactile indicator 2424 c may indicate that the actuator 2416 is notfunctioning. According to one embodiment, different meanings may beconveyed by a single tactile indicator. For example, a short vibrationof tactile indicator 2424 a may indicate the locate receiver powersupply is low, while a longer duration vibration of tactile indicator2424 a may indicate, for example, that the locate receiver is not at thecorrect job location, for example as may be determined by a locationtracking system of the locate receiver. Thus, it should be appreciatedthat the tactile indicators may be used to convey various messages tothe technician.

According to one aspect of the present invention, one or more of thetactile indicators 2424 a-2424 c may operate in response to informationcollected by an environmental sensor and/or operational sensor of thelocate receiver. For example, as described above (e.g., in connectionwith FIG. 19), some embodiments of the present invention provide analert or notification to the locate receiver technician if anout-of-tolerance condition is detected based on a condition sensed by anenvironmental or operational sensor. As explained, the alerts may takeany suitable form including visual and/or audible. In addition, oralternatively, the alerts may be presented via one or more of thetactile indicators. For example, the tactile indicator 2424 c mayvibrate if an out-of-tolerance condition is detected that would beadverse to performance of the locate operation.

According to one embodiment, the nature of operation of each of thetactile indicators in FIG. 24, in terms of what triggers vibration ofthe tactile indicator, the type of vibration (intensity, duration,frequency, pattern, etc.), and the meaning may be controlled by thecontrol electronics 2412. For example, the nature of operation of eachof the tactile indicators may be programmed into a processor of thecontrol electronics (e.g., similar to processor 118, previouslydescribed).

In one example, the tactile sensations programmed for tactile indicator2424 a may be associated with the general operation of locate receiver2400 and/or aspects of the locate operations. In other words, conditionsassociated with the general operation of locate receiver 2400 and/oraspects of the locate operations are communicated to the user viatactile sensations at handle 2414. In this example, tactile sensationsprovided at handle 2414 may be used to indicate any events that mayoccur on and/or any conditions of the locate receiver. Examples oftactile sensations that are provided at handle 2414 by tactile indicator2424 a may include, but are not limited to, the following:

-   -   1. when powering on the locate receiver, a certain tactile        sensation may indicate the start of the boot cycle, followed by        a “ready” tactile sensation;    -   2. a certain tactile sensation may indicate the status of        certain calibration processes and/or testing processes of        components of the locate receiver. This status may be indicated        during or just following the boot cycle. Additionally, this        status may be indicated at any time during the operation of the        locate receiver that any component falls out of calibration;    -   3. a certain tactile sensation may indicate a change in        connectivity of the locate receiver to a network (e.g., dropped        or gained WiFi connectivity);    -   4. a certain tactile sensation may indicate a change in GPS        connectivity (e.g., dropped or gained);    -   5. certain tactile sensations may indicate that the battery        power (e.g., power supply 114) is below certain capacities        (e.g., 75%, 50%, 25% capacity);    -   6. a certain tactile sensation may indicate that the locate        receiver is not oriented correctly (e.g., at the wrong angle);    -   7. a certain tactile sensation may indicate that the sweeping        motion of the locate receiver is not at the correct rate (e.g.,        outside of tolerances because it is either too fast or too        slow);    -   8. a certain tactile sensation may indicate that the signal        strength indicated by detection electronics 131 is acceptable,        too low, or too high;    -   9. a certain tactile sensation may indicate a change in the        depth of the source of the detected electromagnetic field; and    -   10. any combinations thereof.

In one embodiment, the tactile sensations programmed for tactileindicator 2424 b at the joystick 2420 may be associated with userinterface functions. In other words, when the user is using the joystickor buttons to navigate through menus on display 2418, tactile feedbackto the user at the joystick 2420 may be used to communicate, forexample, a validation of certain selections or user interface functions.Examples of tactile sensations that may be provided at joystick 2420 viatactile indicator 2424 b may include, but are not limited to, thefollowing:

-   -   1. a certain tactile sensation may be provided when moving from        option to option of a menu of the display 2418;    -   2. certain tactile sensations may indicate the selection of        different options of a menu of the display 2418. For example:        -   a. a certain tactile sensation may indicate a job started            selection and/or job stopped selection;        -   b. a certain tactile sensation may indicate that landmark            mode was selected as well as a certain type of landmark            selected;        -   c. a certain tactile sensation may indicate that Bluetooth®            communication is enabled and/or disabled;        -   d. a certain tactile sensation may indicate that an invalid            option has been selected. For example, the user has selected            a gas landmark, but no gas facility is indicated on the            current locate operation work order;        -   e. a certain tactile sensation may indicate that a certain            signal frequency range is selected;        -   f. a certain tactile sensation may indicate that certain            signal amplitude range is selected; and    -   3. any combinations thereof.

In one embodiment, the tactile sensations programmed for tactileindicator 2424 c at the actuator 2416 may be associated with operationof the actuator 2416. Examples of tactile sensations that may beprovided via tactile indicator 2424 c include, but are not limited to,the following:

-   -   1. a certain tactile sensation may be provided to indicate the        technician should press the actuator 2416;    -   2. a certain tactile sensation may be provided to indicate the        technician is not applying sufficient force to fully engage the        actuator 2416;    -   3. a certain tactile sensation may be provided to indicate the        technician is applying too great a force to the actuator 2416;        and    -   4. a certain tactile sensation may be provided to indicate the        actuator 2416 has been disabled or enabled.

Tactile sensations may also be generated based on information receivedfrom one or more sources external to the locate receiver, such as, butnot limited to, external systems, external networks, external computingdevices, external business applications, and external instrumentation,among others. For example, the locate receiver (e.g., locate receiver2400) may be in communication with one or more external devices, such asremote computer 150, via a network. The network may be, for example, alocal area network (LAN) and/or a wide area network (WAN). The controlelectronics 2412 may be programmed to generate tactile sensations viaone or more of tactile indicators 2424 a-2424 c based on informationreceived from the remote computer 150.

Thus, further examples of scenarios which may trigger generation of atactile sensation via any one or more of the tactile indicators 2424a-2424 c may include, but are not limited to, the following:

-   -   1. the locate receiver may receive workflow information and/or a        checklist with respect to performing locate operations        according, for example, to U.S. patent application Ser. No.        12/703,809, entitled “Marking Apparatus Equipped with Ticket        Processing Software for Facilitating Marking Operations, and        Associated Methods,” filed Feb. 11, 2010, which application is        hereby incorporated by reference. A certain tactile sensation        may be generated to indicate compliance and/or non-compliance        with the workflow and/or checklist;    -   2. the locate receiver may receive standard operating procedure        (SOP) information with respect to performing locate operations        according to, for example, the Best Practices Version 6.0        document, published in February 2009 by the Common Ground        Alliance (CGA) of Alexandria, Va. (www.commongroundalliance.com)        and/or the Recommended Marking Guidelines For Underground        Utilities as endorsed by the National Utility Locating        Contractors Association (NULCA) of North Kansas City, Mo. A        certain tactile sensation may be generated to indicate        compliance and/or non-compliance with the SOP information;    -   3. the locate receiver may receive wage and hour information        with respect to performing locate operations according to, for        example, the wage and hour guidelines of one or more regulatory        bodies, such as federal, regional, state, and/or local wage and        hour guidelines. For example, a certain tactile sensation may be        generated to indicate compliance and/or non-compliance with the        wage and hour guidelines. Also, a certain tactile sensation may        be generated to indicate, for example, that it is time for a        required break, it is time for lunch, it is the end of the day,        the employee is now in overtime mode for the week, etc.;    -   4. the locate receiver may receive quality assessment        information with respect to performing locate operations        according to, for example, a quality assessment application of        the locate company. A certain tactile sensation may be generated        to indicate that the locate operation has passed and/or failed        the locate company's quality assessment process;    -   5. the locate receiver may receive VWL information with respect        to the current locate operation according to, for example, the        VWL application that is described in U.S. Patent Application        Publication No. 20090238417, entitled “Virtual white lines for        indicating planned excavation sites on electronic images;” which        is incorporated by reference herein in its entirety. A certain        tactile sensation may be generated to indicate that the locate        operation is being performed inside and/or outside of the        boundaries of the associated VWL;    -   6. the locate receiver may receive facilities maps information        with respect to the current locate operation work order. A        certain tactile sensation may be generated to indicate that the        locate operation is approaching the location of a certain        facility that is indicated on the facilities maps associated        with the current locate operation work order. Also, a tactile        sensation may be generated to indicate that certain types of        facilities being located do not match the types of facilities        indicated on the facilities maps;    -   7. the locate receiver may receive information about prior        locate operations (e.g., historical work order information) with        respect to the location of the current locate operation. A        certain tactile sensation may be generated to indicate that the        locate operation is approaching the location of a certain        facility that is indicated in the historical information that is        associated with the current locate operation work order. Also, a        tactile sensation may be generated to indicate that certain        types of facilities being located do not match the types of        facilities indicated by the historical locate information.

It should be appreciated that information about the generation of atactile signal may be included in an electronic record, a message, orany other source of information including the other locate informationdescribed herein. For example, information about whether a tactilesignal was generated, which tactile indicator generated the signal, thetype of signal (e.g., duration, frequency, intensity, etc.), the causeof the signal, the time of the signal (e.g., from a timestamp), and/orthe geo-location at which the signal was issued, may be recorded, amongother things.

Table 19 illustrates an example of an event entry that may be made inresponse to actuation of an actuation system of a locate receiver, inwhich the locate receiver includes a tactile indicator. The illustratedevent entry is similar to that of Table 12, shown and describedpreviously, with the addition of an indication of whether a tactilesignal was generated (e.g., a “yes” or “no” indication being representedby “Y” and “N” for “TCTL”). Information from one or more inputdevices/other components of the locate receiver is recorded with theseevents to provide information about the job in progress.

TABLE 19 Format INFO+ LCTR: (DATE) (TIME) (GPS data) (FACILITY TYPE)(GROUND TYPE) (MAGNETIC FIELD STRENGTH AS % OF FULL SCALE info)(DETECTED SIGNAL FREQUENCY) (GAIN) AMB TEMP info) (SURF TEMP info) (HUMinfo) (LIGHT info) (IMAGE info) (AUDIO info) (OP TEMP info) (COMPASSinfo) (INCL info) (ACC1 info) (ACC2 info) (YAW info) (PROX info) (DH1info) (DH2 info) (TACTILE INDICATION info)<CR><LF> Examples INFO+LCTR:DATE(2009-04-15) TIME(12:04:44) GPS($GPGGA, 120443, 4807.038, N,01131.000, E, 1, 08, 0.9, 545.4, M, 46.9, M,, *47) FACILITY TYPE(YELLOW) GROUND TYPE (PAVEMENT) STRENGTH(80) FREQUENCY(512) GAIN (10)AMB TEMP(73F) SURF TEMP(78F) HUM(31) LIGHT(1500) IMAGE(Y) AUDIO(Y) OPTEMP(97F) COMPASS(243) INCL(−40) ACC1_x_raw(.285) ACC1_x_high(.280)ACC1_x_low(.275) ACC1_y_raw(.385) ACC1_y_high(.382) ACC1_y_low(.380)ACC1_z_raw(.155) ACC1_z_high(.150) ACC1_z_low(.145) (ACC2(!) YAW(!)PROX(15) DH1(67) DH2(!) TCTL(Y)<CR><LF> INFO+LCTR: DATE(2009-04-15)TIME(12:04:45) GPS($GPGGA, 120445, 4807.038, N, 01131.000, E, 1, 08,0.9, 545.4, M, 46.9, M,, *47) FACILITY TYPE (YELLOW) GROUND TYPE (GRASS)STRENGTH(81) FREQUENCY (512) GAIN (10) AMB TEMP(73F) SURF TEMP(78F)HUM(31) LIGHT(1500) IMAGE(Y) AUDIO(Y) OP TEMP(97F) COMPASS(243)INCL(−40) ACC1_x_raw(.285) ACC1_x_high(.280) ACC1_x_low(.275)ACC1_y_raw(.385) ACC1_y_high(.382) ACC1_y_low(.380) ACC1_z_raw(.155)ACC1_z_high(.150) ACC1_z_low(.145) ACC2(!) YAW(!) PROX(15) DH1(67)DH2(!) TCTL(Y)<CR><LF> INFO+LCTR: DATE(2009-04-15) TIME(12:04:46)GPS($GPGGA, 120446, 4807.038, N, 01131.000, E, 1, 08, 0.9, 545.4, M,46.9, M,, *47) FACILITY TYPE (YELLOW) GROUND TYPE (DIRT) STRENGTH(80)FREQUENCY(512) GAIN (11) AMB TEMP(73F) SURF TEMP(78F) HUM(31)LIGHT(1500) IMAGE(Y) AUDIO(Y) OP TEMP(97F) COMPASS(243) INCL(−40)ACC1_x_raw(.285) ACC1_x_high(.280) ACC1_x_low(.275) ACC1_y_raw(.385)ACC1_y_high(.382) ACC1_y_low(.380) ACC1_z_raw(.155) ACC1_z_high(.150)ACC1_z_low(.145) ACC2(!) YAW(!) PROX(15) DH1(67) DH2(!) TCTL(N)<CR><LF>

Table 20 illustrates an example of a data record that may be generatedby a locate receiver including a tactile indicator, as well as variousenvironmental and operational sensors. As shown, the data record mayinclude a “yes/no” indication of whether a tactile signal was generated,as well as information about the type of signal. It should beappreciated that other forms for the data are possible and that otherinformation regarding the tactile indicator may be included, such as anyof the types of information described above.

TABLE 20 Example record of data acquired by locate receiver 2400 uponactuation Record Service provider ID 0482 # act-1 User ID 4815 ReceiverID 7362 Receiver Mode Mode = Peak Timestamp data 12-Jul-2008; 09:35:15.2Geo-location data 2650.9256, N, 08003.5234, W Signal strength (% of 86maximum) Gain 45 Signal frequency (kHz) 1 Facility depth (meters) 3.4Facility type Gas (yellow) Ground type Pavement Locate request dataRequestor: XYZ Construction Company, Requested service address: 222 MainSt, Orlando, FL Temperature (° F.) 75 Heading (degrees) 243 Inclination(degrees) 25 Acceleration (g) (x-axis) 0.75 Acceleration (g) (y-axis)1.20 Acceleration (g) (z-axis) 0.90 Yaw rate (degrees/sec) 10 Distance(cm) 15 Pressure (pounds/in²) 45 Image captured (Y/N) Y Audio captured(Y/N) N Tactile Signal (Y/N) Y Type of Tactile Signal Repeatingvibration; duration 3 seconds

In those embodiments in which a locate receiver includes both a tactileindicator and at least one accelerometer, data from the accelerometer(s)may be used to verify whether a tactile indication was generated, as theaccelerometer data may reflect any physical movement of the locatereceiver, including the physical vibrations caused by a tactileindicator. Thus, referring again to Table 20, for example, theacceleration data may provide verification that the indicated tactilesignal was in fact generated.

FIG. 25 illustrates a locate transmitter that includes a tactileindicator, according to one embodiment of the present invention. Theforegoing discussion with respect to tactile indicators on a locatereceiver is applicable in the context of locate transmitters, such thatmuch of the discussion is not now repeated, as it should be understoodthat the concepts described above are applicable to the locatetransmitter of FIG. 25.

As shown, the locate transmitter 2500 includes a body 2502 having ahandle 2504. The locate transmitter includes a power source 2506, whichmay be and function substantially the same as previously described powersource 114. Also, the locate transmitter 2500 includes controlelectronics 2508, which may be similar to or substantially the same aspreviously described control electronics 112. For example, the controlelectronics 2508 may include a processor, a local memory, a timingsystem, a location tracking system, a user interface, and acommunication interface, one or more of which may be substantially thesame as the corresponding components of control electronics 112. Thelocate transmitter 2500 also includes an applied signal output 2510 forproviding an applied signal along a facility.

Furthermore, the locate transmitter includes a tactile indicator 2512in, on, or otherwise mechanically coupled to the handle 2504. Thetactile indicator 2512 may be substantially the same as any of thetactile indicators 2424 a-2424 c described in connection with FIG. 24.Thus, the tactile indicator 2512 may vibrate or otherwise provide atactile indication to a technician. The tactile indication may be of anysuitable type in terms of pattern, intensity, and duration. Moreover,the tactile indicator 2512 may be configured to provide multipledifferent types of tactile indications, for example with the differenttypes having different meanings. The type and meaning of a tactileindication provided by tactile indicator 2512 may be, in one embodiment,programmed or otherwise controlled by a processor of the controlelectronics 2508, in the same manner as that described above withrespect to tactile indicators 2424 a-2424 c being controlled at least inpart by the processor 118.

The tactile indicator 2512 may be triggered in response to one ofvarious conditions, such as those previously described with respect totactile indicators 2424 a-2424 c that are applicable in the context oflocate transmitters. For example, out-of-tolerance environmental and/oroperational conditions may trigger the tactile indicator 2512. Eventsrelating to the general operation of the locate transmitter 2500 maytrigger a tactile indication, such as but not limited to:

-   -   when powering on the locate transmitter, a certain tactile        sensation may indicate the start of the boot cycle, followed by        a “ready” tactile sensation;    -   a certain tactile sensation may indicate the status of certain        calibration processes and/or testing processes of components of        the locate transmitter. This status may be indicated during or        just following the boot cycle. Additionally, this status may be        indicated at any time during the operation of the locate        transmitter that any component falls out of calibration;    -   a certain tactile sensation may indicate a change in WiFi        connectivity (dropped or gained);    -   a certain tactile sensation may indicate a change in GPS        connectivity (dropped or gained);    -   certain tactile sensations may indicate that the battery power        (e.g., power source 2506) is below certain capacities (e.g.,        75%, 50%, 35% capacity);    -   a certain tactile sensation may indicate that the locate        transmitter is well connected (i.e., a good electrical        connection) or poorly connected (i.e., a poor electrical        connection) to the target underground facility;    -   a certain tactile sensation may indicate that the locate        transmitter is not electrically grounded, or poorly electrically        grounded;    -   a certain tactile sensation may indicate that Bluetooth®        communication is enabled and/or disabled;    -   a certain tactile sensation may indicate that a certain applied        signal frequency range is selected;    -   a certain tactile sensation may indicate that a certain applied        signal amplitude range is selected; and    -   any combinations thereof.

Information received from external sources (e.g., a remote device, suchas a remote computer) may trigger the tactile indicator 2512. Forexample, any of the above-described types of information possiblyreceived by locate receiver 2400 may similarly be received by locatetransmitter 2500 and may trigger a tactile sensation (e.g., checklistinformation, SOP information, wage and hour information, qualityassessment information, VWL information, facilities maps information,and/or information about prior locate operations, among others). Thus,any of the following types of alerts may be generated via tactileindicator 2512:

-   -   an alert to indicate non-compliance with a checklist;    -   an alert to indicate non-compliance with an SOP;    -   an alert based on wage and hour guidelines (e.g., an alert to        indicate that it is time for a required break, it is time for        lunch, it is the end of the day, the locate technician is now in        overtime mode for the week, etc.);    -   an alert from the home office to indicate to the locate        technician to move from his/her present location to another        location to perform an emergency locate operation;    -   an alert to indicate that the locate operation has failed the        locate company's quality assessment process;    -   an alert to indicate that the locate operation is being        performed outside of the boundaries of the associated VWL;    -   an alert to indicate that the selected frequency range and/or        amplitude range of a locate receiver does not match the selected        frequency range and/or amplitude range of the locate        transmitter;    -   an alert to indicate that the signal connection and/or ground        connection of the locate transmitter is poorly connected to the        target underground facility; and    -   an alert to indicate that a component of the locate transmitter        has fallen out of calibration.

It should be appreciated that the examples described above with respectto the types of tactile indications which may generated by tactileindicator 2512, their causes, and their meanings, are not limiting, butrather are provided for purposes of illustration. Other causes oftactile indications are possible, as are other types of tactileindications. Furthermore, while FIG. 25 illustrates a single tactileindicator 2512, not all embodiments of a locate transmitter having atactile indicator are limited in this manner. For example, a locatetransmitter may have one or more tactile indicators according to variousembodiments described herein.

Furthermore, electronic records and event entries may be generated basedon operation of the locate transmitter 2500, which records and entriesmay include an indication of whether a tactile signal was generated, andif so, what kind, at what time, at what location, and whether it wasacknowledged, among other things. Thus, entries and records such asthose of Tables 19 and 20 may be generated in the context of the locatetransmitter 2500.

It should be appreciated that many of the aspects of the presentinvention described above also apply to a combination locate and markingdevice. As explained, a locate receiver is a device typically used tolocate an underground facility, after which the location may be markedusing a marking device. According to one embodiment, a single device mayperform the function of a locate receiver and a marking device, and thusmay be a combination locate and marking device, as described in U.S.patent application Ser. No. 12/569,192, filed on Sep. 29, 2009 underAttorney Docket No. D0687.70010US01 and titled “Methods, Apparatus, andSystems For Generating Electronic Records Of Locate And MarkingOperations, And Combined Locate And Marking Apparatus For Same,” whichis hereby incorporated herein by reference in its entirety. The variousaspects described herein relating to locate receivers may also apply tosuch combination locate and marking devices as those described in U.S.patent application Ser. No. 12/569,192.

XI. Locate Transmitter with Enhanced Ground Probe

According to one embodiment of the present invention, a locatetransmitter includes an enhanced ground probe for determining one ormore characteristics of the ground (or other material) into which it isinserted. When using a locate transmitter in a conductive mode ofoperation, the transmitter may be suitably electrically grounded byconnecting to a ground stake, for example a metal rod inserted into theground. The quality of the electrical grounding may depend oncharacteristics of the ground into which the stake is inserted, such asthe moisture content, iron content, soil type (e.g., sandy, clay, etc.)and pH, among others. Accordingly, one embodiment of the presentinvention provides one or more ground probes for grounding a locatetransmitter that also measures one or more of moisture content, pH, orother characteristics of interest of the ground. FIG. 27 illustrates anon-limiting example.

The locate transmitter 2700 of FIG. 27 may be substantially similar topreviously described locate transmitter 2500, and thus includes some ofthe same reference numbers. In addition, locate transmitter 2700includes a signal lead 2702 (e.g., a wire) terminating with a clamp 2704for clamping to a connection point of a target facility. The signal lead2702, which is connected to the applied signal output 2510, provides theapplied signal to the target facility. The locate transmitter 2700 alsoincludes a ground lead 2706 terminating with one or more ground probe2708. The ground probe 2708 may be configured to be inserted into thephysical ground to establish an electrical ground connection for thelocate transmitter 2700.

The one or more ground probes 2708 may each be configured to sense oneor more of moisture content, iron content, soil type and pH of theground into which it is inserted, using techniques known to those ofskill in the art. The sensed information may be provided to controlelectronics 2508 (e.g., a processor or memory of the controlelectronics) for storage in an electronic record, processing,transmission to an external device (e.g., remote computer 150) or any ofthe other uses of information described herein. According to oneembodiment, an alert may be generated to a technician using the locatetransmitter 2700 if the sensed moisture and/or pH indicate anout-of-tolerance condition, e.g., a condition not suitable for making agood electrical ground. According to one embodiment, the locatetransmitter may be disabled (e.g., any applied signal may be inhibited)in response to detecting such a condition. Other actions may also betaken in response to detecting such a condition, according to thevarious aspects described herein.

It should be appreciated that locate transmitters including a groundprobe of the type illustrated in FIG. 27 need not include tactileindicators or the other features of the locate transmitter 2700. Rather,the locate transmitter 2700 represents a non-limiting example only.

XII. Determination of Distances Between Locate Transmitter andConnection Points

According to another embodiment, it may desirable to know a distancebetween the body of a locate transmitter, the connection point (e.g.,clamp) for connecting to a facility, and the connection point toelectrical ground (e.g., to a ground stake). For example, there may berecommended distances between the ground connection point (e.g., thelocation of a ground stake or ground probe), the body of thetransmitter, and the point at which the transmitter connects to thetarget facility. Referring to FIG. 27 as a non-limiting example, theremay be preferred distances between the body 2502, the clamp 2704 (whenclamped), and the ground probe 2708 (when inserted into the ground orother material). Deviation from such preferred distances may result inelectrical interference, compromising the quality of an applied signal,or otherwise degrading performance of the locate transmitter. Thus,according to one embodiment of the present invention, apparatus andmethods are provided for determining the distances between suchcomponents.

According to a first embodiment, the distances between a locatetransmitter body, a connection point of the locate transmitter to atarget facility, and a ground connection point (e.g., the location of aground stake) may be determined by providing a location tracking system(e.g., a GPS receiver, as previously described) for each of the pointsof interest. For example, referring to FIG. 27, each of the body 2502,clamp 2704, and ground probe 2708 may include a GPS receiver. Thus, thedistances between the components may be determined from the GPS dataprovided by the GPS receivers.

According to another embodiment, the distances between the componentsmay be determined using a landmark mode of the locate transmitter or ofa locate receiver. For example, as previously explained, landmark modefunctionality may allow for recording of geo-location information oflandmarks of interest. According to one embodiment, a locate receiverwith landmark mode functionality may be used to record the geo-locationof each of the body 2502, clamp 2704, and ground 2708, from which thedistances between the components may be determined. Alternatively, thelocate transmitter itself may have landmark mode functionality and maybe used to determined the geo-location of the components of interest.

According to a further embodiment, a locate transmitter may include oneor more proximity sensors which may be used to determine the distancesbetween components. For example, the locate transmitter 2700 may includea proximity sensor which may be implemented to measure a distancebetween the body 2502 and the ground probe 2708. Similarly, the distancebetween the body 2502 and the clamp 2704 may be determined with theproximity sensor.

Other manners of determining the distances between a locate transmitter,a connection point to a target facility, and an electrical groundconnection point are also possible, as the above-described examples arenon-limiting. Furthermore, while the foregoing description referencesthe locate transmitter 2700 as an example, it should be appreciated thatthe techniques may be applied to various types of locate transmittersand that, for example, the locate transmitter need not include a probelike ground problem 2708 for measuring characteristics of the ground.

Information about the distances between the locate transmitter body, theelectrical ground connection point, and the connection point to thetarget facility may be used in any of the manners previously describedfor other types of locate-related information. According to oneembodiment, the information may be recorded in an electronic record.According to another embodiment, an alert may be generated and providedto a technician using the locate transmitter if the determined distancesdo not satisfactorily compare to pre-determined or accepted values. Forexample, if the distances are too short (e.g., indicating thepossibility of electrical interference), an alert may be generated.Moreover, according to one embodiment the locate transmitter may bedisabled (e.g., generation of the applied signal may be inhibited) ifthe measured distances do not satisfactorily compare to pre-determinedor accepted values. Other types of responses are also possible, as thoselisted are non-limiting examples.

XIII. Conclusion

As discussed herein, a wide variety of information/data may be acquiredand analyzed in connection with locate operations, for a variety ofpurposes. The data of interest that may be acquired and analyzed mayinclude, but is not limited to, timestamp data, geo-location informationof detected facilities, geo-location information of environmentallandmarks, direction information, any information included in thestandard data stream of the locate tracking system (e.g., GPS system),color/type of detected facilities, ID information (e.g., individual,vehicle, wage and/or hour compliance), battery status of the locatedevice, wired/wireless connection status, Bluetooth® signal strength,storage capacity of the local memory, temperature, humidity, lightlevel, movement of the locate device, mode of operation of the locatedevice, charging state of the locate device (e.g., charging/notcharging), alerts against expectations in performance, and anycombination thereof.

The information, such as shown in various tables herein, that may beacquired by use of the data acquisition system and methods describedherein, may be used for any purpose. In an embodiment, the informationof the data acquisition system may be analyzed against expected locateoperations in order to gain benefits in, for example, operatingefficiency, personnel management, inventory management, quality control,training operations, safety, customer satisfaction, and the like.

Additionally, the information that is acquired by use of the dataacquisition system and the methods of the present disclosure may becorrelated to other aspects of locate and marking operations. Forexample, the locate device data streams (e.g., respective event entriesor one or more electronic records transmitted by the locate device) maybe correlated to other data streams of multiple locate devices or anyother devices in order to aggregate, assess, evaluate, draw insightsfrom, take action on this information, and any combination thereof.Correlating disparate data streams may be useful in order to betterinterpret and/or gain new interpretations that are useful. For example,by analyzing the aggregated data, field service providers may gainvisibility into the distributed workforce, may take corrective and/orany other constructive action to improve process management, may improveand/or develop best practices, and any combination thereof. In anembodiment, certain trends may be identified by correlating historicalrecords of the amount of time that is spent performing locate andmarking operations to other information, such as, but not limited to,the time of day, time of year, address of the locate site, experience ofthe locate technician, weather conditions, heavy or light traffic times,and the like.

While various inventive embodiments have been described and illustratedherein, those of ordinary skill in the art will readily envision avariety of other means and/or structures for performing the functionand/or obtaining the results and/or one or more of the advantagesdescribed herein, and each of such variations and/or modifications isdeemed to be within the scope of the inventive embodiments describedherein. More generally, those skilled in the art will readily appreciatethat all parameters, dimensions, materials, and configurations describedherein are meant to be exemplary and that the actual parameters,dimensions, materials, and/or configurations will depend upon thespecific application or applications for which the inventive teachingsis/are used. Those skilled in the art will recognize, or be able toascertain using no more than routine experimentation, many equivalentsto the specific inventive embodiments described herein. It is,therefore, to be understood that the foregoing embodiments are presentedby way of example only and that, within the scope of the appended claimsand equivalents thereto, inventive embodiments may be practicedotherwise than as specifically described and claimed. Inventiveembodiments of the present disclosure are directed to each individualfeature, system, article, material, kit, and/or method described herein.In addition, any combination of two or more such features, systems,articles, materials, kits, and/or methods, if such features, systems,articles, materials, kits, and/or methods are not mutually inconsistent,is included within the inventive scope of the present disclosure.

The above-described embodiments can be implemented in any of numerousways. For example, the embodiments may be implemented using hardware,software or a combination thereof. When implemented in software, thesoftware code can be executed on any suitable processor or collection ofprocessors, whether provided in a single computer or distributed amongmultiple computers.

The various methods or processes outlined herein may be coded assoftware that is executable on one or more processors that employ anyone of a variety of operating systems or platforms. Additionally, suchsoftware may be written using any of a number of suitable programminglanguages and/or programming or scripting tools, and also may becompiled as executable machine language code or intermediate code thatis executed on a framework or virtual machine.

In this respect, various inventive concepts may be embodied as acomputer readable storage medium (or multiple computer readable storagemedia) (e.g., a computer memory, one or more floppy discs, compactdiscs, optical discs, magnetic tapes, flash memories, circuitconfigurations in Field Programmable Gate Arrays or other semiconductordevices, or other non-transitory medium or tangible computer storagemedium) encoded with one or more programs that, when executed on one ormore computers or other processors, perform methods that implement thevarious embodiments of the invention discussed above. The computerreadable medium or media can be transportable, such that the program orprograms stored thereon can be loaded onto one or more differentcomputers or other processors to implement various aspects of thepresent invention as discussed above.

The terms “program” or “software” are used herein in a generic sense torefer to any type of computer code or set of computer-executableinstructions that can be employed to program a computer or otherprocessor to implement various aspects of embodiments as discussedabove. Additionally, it should be appreciated that according to oneaspect, one or more computer programs that when executed perform methodsof the present invention need not reside on a single computer orprocessor, but may be distributed in a modular fashion amongst a numberof different computers or processors to implement various aspects of thepresent invention.

Computer-executable instructions may be in many forms, such as programmodules, executed by one or more computers or other devices. Generally,program modules include routines, programs, objects, components, datastructures, etc. that perform particular tasks or implement particularabstract data types. Typically the functionality of the program modulesmay be combined or distributed as desired in various embodiments.

Also, data structures may be stored in computer-readable media in anysuitable form. For simplicity of illustration, data structures may beshown to have fields that are related through location in the datastructure. Such relationships may likewise be achieved by assigningstorage for the fields with locations in a computer-readable medium thatconveys relationship between the fields. However, any suitable mechanismmay be used to establish a relationship between information in fields ofa data structure, including through the use of pointers, tags or othermechanisms that establish relationship between data elements.

Also, various inventive concepts may be embodied as one or more methods,of which an example has been provided. The acts performed as part of themethod may be ordered in any suitable way. Accordingly, embodiments maybe constructed in which acts are performed in an order different thanillustrated, which may include performing some acts simultaneously, eventhough shown as sequential acts in illustrative embodiments.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Multiple elements listed with“and/or” should be construed in the same fashion, i.e., “one or more” ofthe elements so conjoined. Other elements may optionally be presentother than the elements specifically identified by the “and/or” clause,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, a reference to “A and/or B”, when usedin conjunction with open-ended language such as “comprising” can refer,in one embodiment, to A only (optionally including elements other thanB); in another embodiment, to B only (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

As used herein in the specification and in the claims, “or” should beunderstood to have the same meaning as “and/or” as defined above. Forexample, when separating items in a list, “or” or “and/or” shall beinterpreted as being inclusive, i.e., the inclusion of at least one, butalso including more than one, of a number or list of elements, and,optionally, additional unlisted items. Only terms clearly indicated tothe contrary, such as “only one of” or “exactly one of,” or, when usedin the claims, “consisting of,” will refer to the inclusion of exactlyone element of a number or list of elements. In general, the term “or”as used herein shall only be interpreted as indicating exclusivealternatives (i.e. “one or the other but not both”) when preceded byterms of exclusivity, such as “either,” “one of,” “only one of,” or“exactly one of.” “Consisting essentially of,” when used in the claims,shall have its ordinary meaning as used in the field of patent law.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively, as set forth in the United States Patent Office Manual ofPatent Examining Procedures, Section 2111.03.

1. A device for use in a locate operation to detect a presence orabsence of an underground facility, the device comprising: at least oneof: transmitter circuitry to generate an applied signal to be appliedalong the underground facility; and a receiver antenna configured todetect a magnetic field from the underground facility; a memory to storeprocessor-executable instructions; at least one communication interface;and at least one processor communicatively coupled to the memory, the atleast one communication interface, and the at least one of thetransmitter circuitry and the receiver antenna, wherein upon executionof the processor-executable instructions, the processor: controls the atleast one communication interface to receive environmental informationregarding at least one environmental condition of an environment inwhich the device is located; and stores at least some of the receivedenvironmental information in the memory.
 2. The device of claim 1,wherein the device is a locate transmitter comprising the transmittercircuitry.
 3. The device of claim 1, wherein the device is a locatereceiver comprising the receiver antenna.
 4. The device of claim 1,wherein the at least one environmental condition is ambient temperature.5. The device of claim 1, wherein the at least one environmentalcondition is ambient humidity.
 6. The device of claim 1, wherein the atleast one environmental condition is an altitude of a location at whichthe device is located.
 7. The device of claim 1, wherein the at leastone communication interface communicatively couples the device to anetwork, and wherein the environmental information is received over thenetwork.
 8. The device of claim 7, wherein the network is the Internet.9. The device of claim 1, wherein the at least one communicationinterface is a wireless communication interface.
 10. The device of claim9, wherein the at least one communication interface is configured towirelessly couple the device to a network.
 11. The device of claim 1,wherein the at least one environmental condition is at least one firstenvironmental condition, and wherein the device further comprises atleast one input device communicatively coupled to the at least oneprocessor and configured to sense at least one second environmentalcondition of the environment in which the device is located and providean output signal to the at least one processor indicative of the atleast one second environmental condition.
 12. The device of claim 11,wherein upon execution of the processor-executable instructions, theprocessor processes in combination the output signal of the at least oneinput device and the environmental information received by the at leastone communication interface.
 13. The device of claim 11, wherein the atleast one first environmental condition differs from the at least onesecond environmental condition.
 14. The device of claim 1, wherein, uponexecution of the processor-executable instructions, the processor:controls the at least one communication interface to receive theenvironmental information periodically.
 15. The device of claim 1,further comprising a location tracking system configured to provide tothe processor an indication of a location of the environment in whichthe device is located, and wherein upon execution of theprocessor-executable instructions, the processor: controls the at leastone communication interface to receive the environmental informationregarding the at least one environmental condition of the environmentbased on the indication of the location provided by the locationtracking system.
 16. A method for performing a locate operation todetect a presence or absence of at least one underground facility usinga locate device, the method comprising: A) doing at least one of: i)transmitting an applied signal to the at least one underground facility;and ii) detecting a magnetic field emitted from the at least oneunderground facility; B) receiving, via at least one communicationinterface of the locate device, environmental information regarding atleast one environmental condition of an environment in which the locatedevice is located; and C) logging into local memory of the locate devicelocate information relating at least in part to A) and B).
 17. Themethod of claim 16, wherein the locate device is a locate transmitterand wherein A) comprises transmitting an applied signal to the at leastone underground facility.
 18. The method of claim 16, wherein the locatedevice is a locate receiver, and wherein A) comprises detecting amagnetic field emitted from the at least one underground facility. 19.The method of claim 16, wherein B) comprises receiving an ambienttemperature of the environment in which the locate device is located.20. The method of claim 16, wherein B) comprises receiving a humidity ofthe environment in which the locate device is located.
 21. The method ofclaim 16, wherein B) comprises receiving an altitude of a location atwhich the locate device is located.
 22. The method of claim 16, whereinthe at least one communication interface communicatively couples thelocate device to a network, and wherein B) comprises receiving theenvironmental information over the network.
 23. The method of claim 22,wherein the network is the Internet.
 24. The method of claim 22, whereinthe network is a local area network.
 25. The method of claim 16, whereinthe at least one communication interface is a wireless communicationinterface and wherein B) comprises wirelessly receiving theenvironmental information.
 26. The method of claim 25, wherein the atleast one communication interface is configured to wirelessly couple thelocate device to a network, and wherein B) comprises wirelesslyreceiving the environmental information over the network.
 27. The methodof claim 16, wherein the at least one environmental condition is atleast one first environmental condition, and wherein the method furthercomprises: D) detecting, via at least one input device of the locatedevice, at least one second environmental condition of the environmentin which the locate device is located, and wherein C) comprises logginginto local memory of the locate device locate information relating atleast in part to A), B) and D).
 28. The method of claim 27, furthercomprising: E) processing in combination the locate information relatingto B) and D).
 29. The method of claim 27, wherein the at least one firstenvironmental condition differs from the at least one secondenvironmental condition.
 30. The method of claim 16, wherein B)comprises receiving the environmental information periodically.
 31. Themethod of claim 16, wherein B) is performed in response to A).
 32. Themethod of claim 16, further comprising: D) receiving, from a locationtracking system, an indication of a location of the environment in whichthe locate device is located, and wherein B) comprises receiving theenvironmental information based on the received indication of thelocation of the environment.
 33. At least one computer readable storagemedium storing processor-executable instructions, which when executed byat least one processor, perform a method for facilitating a locateoperation to detect a presence or absence of at least one undergroundfacility using a locate device, the method comprising: A) receiving, viaat least one communication interface of the locate device, environmentalinformation regarding at least one environmental condition of anenvironment in which the locate device is located; and B) logging intolocal memory of the locate device at least some of the environmentalinformation received in A).